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HEALTH READER 




















HEALTH READER 

PHYSIOLOGY— HYGIENE—NUTRITION 


By 

HARVEY W. WILEY, M.D. 

Formerly chief chemist of the United States Department of 
Agriculture. Editor of “Good Housekeeping's" Bureau 
of Foods , Sanitation, and Health. Author of “ Foods 
and Their Adulterations 11 Principles and Practice 
of Agricultural Analysis u The Lure of the 
■Land,” “Not by Bread Alone" 


Illustrated by 

B. F. WILLIAMSON and NED HADLEY 


RAND McNALLY & COMPANY 

NEW YORK 


CHICAGO 


Copyright, 1916 

By Harvey W. Wiley, M.D. 



JAN 13 191/ 1 



TRANSFERRED from 
copyright office 

m 3 m 



A FOREWORD 

I believe it was George Ade who said, “If you want to 
uplift, get beneath.” This sentiment is peculiarly appli¬ 
cable to the study of physiology in the schools. Such 
terms as “anatomy,” “physiology,” and “hygiene” 
terrify the children, and to a certain extent make them 
antagonistic to the study. I have long thought that the 
proper way to get children interested in this matter was 
to make the subject a living one. I have sought to get 
entirely under it and to present it in a vital way. My 
experience is that children are easily interested in matters 
that pertain to their daily life if we go at it in the proper 
spirit. Instead, therefore, of the dry details of physi¬ 
ology, I have tried to lead the child into the midst of 
the phenomena of the life he is living and to tell him in 
simple language of the character of the environment in 
which he lives. 

I begin by taking him outdoors and allowing the wind 
to blow in his face. I lead him to the fireplace and let 
him warm his fingers. I take him to the spring and show 
him the water that he drinks. I go with him into the 
fields to watch the growing food. I visit with him the 
mills where this food is being prepared for consumption. 
I tell him of those things which are vitally related to his 
daily life and which are the groundwork of his health 
and growth. I have endeavored to put the material 
into the form in which the child naturally absorbs it. 
The child is an interrogation point. He asks questions. 
I have taken the questions which have been suggested 
to me by talking with children, and have tried to answer 


VI 


A FOREWORD 


the questions they have put to me. While i;his method 
of preparing a physiology is novel and radical, to my mind 
it seems natural and workable. With the help of the 
teacher the child will at once become interested in the 
phenomena of existence. The study will not be a bur¬ 
den, but a revelation and a pleasure. 

While it has seemed advisable in some places to use 
words which children do not understand, their meanings 
have been given so that they may know what they are 
reading about. The dry details of the usual form of 
study on this subject have been entirely eliminated. 
The child who reads this book properly under competent 
instructors will have a new view of life, a better under¬ 
standing of his environment, and a clearer conception 
of what is good for his health. He will be asking himself 
continually, when new duties and new pleasures present 
themselves, or new foods come to his attention, this 
question: Is it good for me? 

Harvey W. Wiley 

Washington, D.C. 

April, 1916 


THE CONTENTS 


A Foreword .v 

PART ONE 

CHAPTER 

I. The Air We Breathe .i 

II. The Elements of the Air .... 6 

III. The Organs of Breathing . . .21 

IV. How Mosquitoes and Flies Endanger 

Health.58 

V. Dust in the Air.64 

VI. A Study of Ventilation.73 

VII. A Study of Temperature .... 78 

VIII. The Circulation.84 

IX. A Study of Combustion.89 

X. The Temperature of the Body . 93 

XI. The Skin and Its Functions . . . 104 

XII. Water and Its Function in Health . 111 

PART TWO 

XIII. Food and Why We Need It. . . 129 

XIV. The Articles of Food.131 

XV. The Flavor of Foods.136 

XVI. Differences in Foods. . . 142 

XVII. A Study of the Articles of Food. . 155 

XVIII. The Preparation of Bread Foods . 186 

XIX. Vegetables and Fruits.193 

XX. Animal Foods: Flesh, Fish, Fowl, Milk, 

and Eggs.201 

XXI. Preserving Foods.212 

XXII. Nuts as Food.226 

XXIII. Beverages.234 

XXIV. Tobacco and Its Dangers .... 262 

XXV. Confections, Sirups, and Pastry . . 265 

vii 












THE CONTENTS 


viii 


PART THREE 

CHAPTER 

XXVI. How Do We Grow?. 

XXVII. The Process of Digestion .... 
The Teeth and Their Function 
The Salivary Glands and Their 

Function. 

A Study of Swallowing .... 
The Function of the Stomach in 

Digestion. 

A Study of the Small Intestine . 
A Study of the Liver and the Pan¬ 
creas . 

A Study of the Spleen .... 
A Study of the Large Intestine 
XXVIII. A Study of the Kidneys .... 

XXIX. How Foods Are Absorbed .... 

XXX. The Blood Stream. 

XXXI. A Study of the Nervous System . 

The Brain. 

The Spinal Cord. 

The Nerves. 

XXXII. A Study of the Senses. 

The Sense of Sight. 

The Sense of Smell. 

The Sense of Taste. 

The Sense of Hearing. 

The Sense of Touch. 

The Sense of Hunger. 

The Sense of Thirst. 

XXXIII. A Study of Sleep. 

XXXIV. Physical Exercise. 

XXXV. The Value of Health. 

A Pronouncing Vocabulary . 

The Index . 


283 

3i5 

3i5 

327 

329 

333 

342 

345 

349 

35 i 

357 

361 

366 

375 

375 

379 

385 

392 

392 

404 

409 

416 

422 

43i 

433 

436 

449 

456 

459 

463 











HEALTH READER 

PART ONE 

I. The Air We Breathe 

What is the air? The air is an invisible gas, 
without taste or smell. It covers the whole 
surface of the earth and enters into every hole 
and crack in the ground. It also enters the 
ground itself, finding its way to a great depth 
between the particles of soil. 

You have felt the wind blow in your face, 
have you not? 

Once, perhaps, 
your cap was 
carried away by 
the wind, and 
you ran after 
it as fast as 
you could. But 
the same wind 
raised such a 
cloud of dust 
you could hard-, 
ly see which 
way to run. Fortunately the cap struck against 
a tree or fence, or against the curbstone, and 



A lively chase 


HEALTH READER 


you captured it, breathing deeply and quickly 
as a result of your chase. 

What is the wind? Wind is air in motion. 
Perhaps in a violent wind storm you have seen 
a tree blown down, a house unroofed, or a 
signboard blown into the street. If you live 
near water you have watched the sailboats driven 
swiftly through the water, and you have seen 
the high waves crested or white with spray. 
What is it that drives the boats? What pro¬ 
duces the waves? It is the wind. 

What becomes of the wind when it stops 
blowing? When it stops blowing, the wind, 
which is air in motion, becomes still air, or air 
at rest. Have you looked at a pond of water? 



A sailboat being driven swiftly through the water by wind 


• THE AIR WE BREATHE 


3 



There you see water at rest. Have you seen 
a creek or a river? There you see water in 


A pond and a creek, showing water at rest and in motion 

motion. We say that the water in the creek 
is flowing. The wind is flowing air. 

Why can we not see the air? We cannot see 
the air because it has no color. But we can feel 
it. Move a fan slowly — you feel no resistance. 
Move it rapidly — you feel you are pushing it 
through something. That something is the air. 
The fan moves the air out of the way and 
sets it in motion. That makes the wind. You 
feel the wind against your face, but you cannot 
see it. 

Has the air weight? Yes, it is quite heavy. 
Put o m end of a tube or straw in a glass of 




4 


HEALTH READER 


water. Then suck the air out of the tube. 
The pressure of the air on the water outside 
of the tube will drive the 
water into your mouth. 
The common water pump 
is such a tube. You take 
the air out of the tube 
\ of the pump by working 
the pump handle. The air 
pressing on the water in 
the well drives it into the 
tube as fast as the air is 
removed from the tube. 

You can easily make a 
little pump. Take any 
tube—a glass one is best, 
because you can see 
through it. Now make a 
plunger by wrapping the 
lower end of a stick with 
a string until the plunger 
Place the end of the tube 
and draw the plunger up 



A well pump 
a, handle; b, piston; valve 
in piston; d, valve at top of 
suction pipe e; e, suction pipe 
to water well /; /, water in well 


fits snug in the tube, 
in a glass of water 
slowly. By doing this you lift the air out of the 
tube. If the plunger fits so that the air does not 
leak in, the water will rise in the tube and keep 
in touch with the end of the plunger. You do 
not lift the water. You lift the air in the tube. 
The pressure or weight of the air on the water 




























THE AIR WE BREATHE 


5 


outside of the.tube forces the water into the 
space in the tube from which you lifted the air. 

What happens if the 
lower end of the tube 
is closed? This you 
may easily discover. 

The plunger pre¬ 
pared as described 
is generally called a 
piston. Oil the pis¬ 
ton head, that is, the 
end that fits tight in 
the tube, so that it 
works easily. Place 
your finger over the 
end of the tube so 
as to close it tight. 

Then try to draw up ^ homemade pump for demonstrating 

the piston. You will *>, piston 

find this very difficult to do. Why? Because 
you are lifting the air. You will also find that 
your finger is held firmly pressed against the 
end of the tube. 



QUESTIONS TO HELP THE PUPIL 

i. What is air? 2. How can you tell that air is about 
you? 3. What is wind? 4. What have you seen the 
wind do? 5. Why can you not see the air? 6. How do 
you know the air has weight? 7. What makes the water 
rise in a pump? 8. How can you make a water pump? 
















II. The Elements of the Air 

What have you learned about air? You have 
learned that air is an invisible gas without 
taste or smell. You can feel it, measure it, and 
weigh it. Now you all want to know what a 
gas is and how a gas differs from other forms 
of matter. 

What are the forms of matter? All the forms 
of matter with which we are familiar are of 

three classes: 
solid, liquid, 
and gaseous. 
A solid body, as 
we all know, 
sticks r together, 
4 ^eeps its form, 
and can be 
fashioned or 
made into various shapes. A liquid body, on the 
other hand, keeps its form only if held together 
by the walls of a container or vessel, as water 
in a cup. Pour water into a cup until it is full. 
Now if there is a hole in the bottom of the, cup 
the water will at once begin to run out ( and will 
keep running out of this hole until the cup is 
empty. 

If you look at water or any other liquid in an 



6 


THE ELEMENTS OF THE AIR 


7 



A pail of water, showing the 
level surface of a liquid 


open vessel you will find that the top of it is 
always level. Now what is it to be level? 
That seems a simple ques- 
tion, and yet it is a very 
important one. To be 
level, a surface must fit 
exactly with the surface of 
the earth, if the earth were 
perfectly smooth; that is, if 
there were • no hills, no hol¬ 
lows, no river beds, no sea beds on it. The 
free or upper surface of a liquid is always level, 
because of the flowing nature of the liquid itself. 

How does a gas differ from a solid and a liquid? 
A solid has a fixed shape; a liquid has no 
fixed shape, but it occupies a limited space; 
a gas fills the space it is put in, whatever the 
size or shape of the space-. All the surfaces of 
a solid are limited. The top,surface, the side 
surfaces, and the under surface, all are unchang¬ 
ing and limited, just as a block is always- the 
same size and shape wherever it is. A liquid 
has only one surface limited—that is, its upper 
surface. A gas has no surf ace limited; it moves 
in all directions. Air is a gas. 

Standing by a pool of water on a foggy morn- 
ing, you may see a rough stone at the water’s 
edge, the smooth surface of the water, and the 
fog, which seems to extend everywhere. Thus, 


8 


HEALTH READER 



you observe at the same time a solid (stone), 
a liquid (water), and a gas (fog). Fog is not 
really a gas, but it makes you see the 
// /a w wa ter in the air, which is. 

By what means can you discover how 
a gas acts? You can discover how a 
gas acts only by observing a gas that 
has color. Air has no color, so air 
cannot be used for your experiment. 
But there are gases that have colors, 
and by means of these colored gases 
we can see how the air acts. Place a 
small quantity of a colored gas (chlo¬ 
rine) in a glass vessel from which a part 
of the air has been drawn, thus forming 
what we call a partial vacuum. You 
will see that almost instantly the gas 
will fill all parts of the vessel. Water 
will run only downward; a gas will run 
in every direction. 

How far upward does the air extend? 
No one knows exactly. No explorer, 
no mountain climber, no aviator, has 
been more than three or four miles 
above the level of the sea. Yet air 
is still found there. But we do know 
A barometer that th e a * r g e t s thinner and thinner, 
until somewhere, very far up, it ceases to exist. 
If we climb a high mountain and carry with 














THE ELEMENTS OF THE AIR 


9 


us a barometer, an instrument which measures 
the pressure of air by means of mercury in a 
glass tube, we find that the higher we climb 
the lower is the mercury column in the barom¬ 
eter. The pressure of the air decreases because 
the higher we climb the more air we have below 
us, and the less above us. When you have gone 
up a mile you will find it more difficult to 
breathe than at the lower level where you live. 
Now if you breathe as you usually do, you will 
feel suffocated. You must breathe fast and 
deeply in order to get enough air. Two or three 
miles farther up, breathing becomes very diffi¬ 
cult. At a still greater height it is impossible to 
breathe at all and life ends. 

Of how many kinds of matter is air composed? 
One need not be a physiologist or any other kind 
of learned person to be interested in what makes 
up the air. You want to know whether the air 
is made up of more than one kind of matter. 
If you put a marble, a lump of sugar, and a bul¬ 
let into the same box they may all be the same 
shape and the same size, but you know you have 
more than one kind of matter in that box. Now 
we may suppose the air to be made up of spheres 
like marbles, but so small we cannot see them. 

Are these little particles all of the same, kind? 
No, the atmosphere is made up principally of 
two kinds of little spheres, so mixed together 


10 


HEALTH READER 


that you cannot detect any difference in the 
atmosphere in different places. About four 
fifths of the air is made up of little particles 
of a gas called nitrogen , and about one fifth of 
little particles of another gas called oxygen. 
Many particles of other substances are scattered 
among these, but not in great quantities. 

If you drop a little acid on a piece of limestone 
you will see an effervescence or a bubbling, and 


a gas will es¬ 
cape. That gas 
is called carbon 
dioxide. It is the 
same kind of gas 
that is formed in 
the body when 
food is burned to 
make your body 
warm. For, 
just as wood or 
coal is burned in 
a stove to keep 
the house warm, 
so a portion of 
the food we eat 
is burned in the 
body to keep it 



a 


A—How plants breathe 

a, root hairs which absorb soluble mineral 
substances from the soil 


warm. This gas also forms when anything 
is burned by fire.. Particles of this gas are 




THE ELEMENTS OF THE AIR 


ii 


always present in the air. There are about 
four parts of this gas to ten thousand parts of 
air. It has im- g 

portant work to 
do. It is neces 
sary in the 
growth of plants 
The plant takes 
these little par¬ 
ticles of carbon 
dioxide gas, in¬ 
visible to us, 
and uses them 
to form woody 

cmrI on cror B —Under side of leaf as seen through a 
liuei etna bugcii microscope 

and starch. But mouths or stomata; b, leaf cells 

the plants do not use the carbon dioxide par¬ 
ticles entirely. These particles consist of a 
compound or mixture of carbon and oxygen 
The plants take only the carbon contained in 
the particles, the same substance you see in 
coal and in diamonds. After separating the 
carbon from the carbon dioxide particles, the 
plants send back the oxygen into the air. Thus 
there is a continual contest going on in nature. 
The fires that burn in the stoves and furnaces, 
the burning of food in the body, and the burning 
gas jet or lamp are continually taking oxygen 
from the air and throwing little particles of 



12 


HEALTH READER 


carbon dioxide back into the air. The plants 
are continually taking these particles of carbon 
dioxide, absorbing their carbon, and turning the 
oxygen back into the air. In this way the air 
always contains oxygen sufficient for all the 
purposes of life. Because of the action of 
plants on the carbon dioxide in the air, house 
plants are useful and healthful. 

There are also little particles of water in the 
air. Usually you do not think of water as a 
gas. Yet water exists everywhere as a gas. 
Ordinarily you cannot see it, but when so 
much of it goes into the air that it forms a 
cloud or a fog, then of course it may be seen. 
Although as a rule you cannot see water in 
the air, it is there, and in very considerable 
quantities. 

There are also a number of other substances 
in the air which no one had ever known about 
until within the last few years. These sub¬ 
stances have been discovered very recently. 
The air is like the world. For a long time 
people did n’t know there was such a continent 
as America. Until a short time ago no one 
had ever seen the earth at the poles. We are 
continually making discoveries in the earth’s 
surface. We are also making discoveries in the 
composition of the atmosphere. One of these 
is the discovery of argon. If we could see all 


THE ELEMENTS OF THE AIR 


13 


the different particles present in the air we 
should find little particles of argon. Argon is 
a Greek word meaning “inactive,” and it is 
applied to these particles- because they are 
extremely inactive. Argon particles do not 
make intimate acquaintances of the particles 
of any other gas. They are like people who 
prefer to stand off in a corner by themselves. 

Then again we should see, if we had eyes 
that were able to see, that there are still other 
little particles wandering around in the atmos¬ 
phere. v These are called krypton , a word which 
means “hidden,” and was given to these par¬ 
ticles because they had been so long concealed 
that nobody even knew they existed. We 
should see still other little particles, not so 
numerous but nevertheless quite abundant, 
called xenon. This word means “stranger,” 
and these particles were so called because it 
was so long before anybody made their ac¬ 
quaintance. 

All of these substances make up the atmos¬ 
phere we breathe, and none of them is closely 
combined with any of the others. It is just 
a simple mixture. Every time you breathe 
you take into your lungs a certain amount of 
this mixture made up of all these substances. 
They are what are called natural constituents , 
or parts of the air. The air is pure when it 


14 


HEALTH READER 


contains these natural constituents in the quan¬ 
tities in which ordinarily they are to be found 
in the great ocean of air surrounding us. 

When is air impure? The air is impure when 
it contains too much or too little of any one of 
its natural constituents. For instance, if oxy¬ 
gen, which is the most active substance in 
the air and the one on which the continuation 
of life depends, is diminished in quantity the 
air is impure. If, on the other hand, oxygen 
is increased in quantity the air is also impure. 
If the quantity of oxygen is decreased, then we 
have to take in a great deal more air to perform 
the functions of life; if it is increased the burn¬ 
ing of the foods and tissues in the body would 
go on more rapidly and we should become ill 
and have fever. If there were no oxygen in the 
air we could not live; also, if the air consisted 
entirely of pure oxygen it would speedily cause 
us to die. 

The air is also impure if unnatural and nox¬ 
ious or harmful substances are present in it. If 
you approach a gas factory you will smell an odor 
due to the presence in the air of little particles 
of bad-smelling gases. If you go near a refrig¬ 
erating or ice-making establishment you are 
likely to notice an odor of ammonia which has 
escaped from the condensing machinery. If 
you happen to be in Chicago, especially when 


THE ELEMENTS OF THE AIR 


15 


the weather is warm, you may distinguish the 
odor of the stockyards at a distance of a mile 
or more from them if the wind is blowing from 
that direction toward you. 

The air often carries in this way not only 
particles of gaseous matter which have a bad 
odor, but it may also contain gaseous par¬ 
ticles having a pleasant odor. The odor of 



A hayfield in midsummer 


new-mown hay is familiar to all who live in 
the country. Everybody has been told about it 
or has read poems about it. The scent of the 
rose and the odor of the cornfield and the smell 
of the forest are familiar to almost every one. 
A number of perfumes owe their power to the 
fact that they fill the air with small particles of 








16 HEALTH READER 

good-smelling material. The attar of roses, 
the eau de Cologne , and all the various perfumes 
which a young lady puts on her handkerchief 
have these properties. 

In our homes we are all familiar with the 
odors, generally pleasant, of the cooking dinner. 
Sometimes, though, these odors are unpleasant; 
for instance, when the odor of boiled cabbage 
or of frying fish fills the house. 

All these instances illustrate the many sub¬ 
stances which the air may contain, not to speak 
of the dust and/ solid particles which may also 
be present in the air. It is evident that the 
air is a really very complex mixture, but our 
attention is specially fixed on the fact that its 
chief characteristic, so far as human life is 
concerned, is its property of supporting life. 

Can we live without air? Most of you have 
heard of accidents in which people lost their 
lives either by drowning or by suffocation. Acci¬ 
dents of this kind forcibly illustrate the fact 
that we can live only a few minutes without 
air. If you try to hold your breath, you experi¬ 
ence no discomfort for the first few seconds. 
But no matter how strong the will power may 
be, no one can hold his breath long enough to kill 
himself. Nature asserts her supreme authority 
over the will of the individual. 

Divers who have practiced for a long while 


THE ELEMENTS OF THE AIR 


i7 



have been known to keep their heads under 
water for several minutes. This is possible, 
however, only to persons who have great lung 
capacity, and who have filled their lungs full of 
air before submerging their heads in the water. 
Such rare examples, however, cannot be re¬ 
garded as a measure of the length of time we 


























i8 


HEALTH READER 


can do without breathing. Air is a constant, 
necessary, and indispensable element of life. 

What takes place during the process of breathing? 

The process of breathing is a simple, mechanical 
action, involuntary as a rule, by means of which 
air is taken into and sent out from the lungs. 
It is easy to breathe purposely, but as a rule 
breathing is wholly involuntary. We are asleep 
about one third of our time, and during sleep 
we are wholly unconscious of breathing. Unless 
we are taking exercise or purposely turn our 
attention directly to it, the act of breathing is 
just as unconscious during our waking hours 
as it is during sleep. 

How often do we breathe ? There is no rule by 

means of which we can measure the frequency 
of breathing, except by counting for each per¬ 
son. It varies greatly in different individuals 
and at different ages. We do not breathe nearly 
so frequently when we "are at rest as when we 
are engaged in exercise. In ordinary circum¬ 
stances, that is, when working at his ordinary 
occupation, the grown person will breathe about 
eighteen times a minute. Children breathe 
more frequently than grown persons, and old 
persons also breathe more frequently than 
people in the prime of life. Sickness also causes 
a difference in the rate of breathing. ^ Usually 
the more severe the disease, the more rapid the 


THE ELEMENTS OF THE AIR 


i9 


breathing. Especially is this true in diseases 
of the heart and the lungs. 

How much air do we breathe at one time? This 
too can be answered only in a general way. The 
amount of air which is taken at each breath 
depends upon the size of the lungs of the 
individual and the way he uses them. If we 
practice deep breathing—that is, if we make a 
conscious effort to fill the lungs as full as we 
can—we soon acquire an unconscious habit of 
deep breathing, thus increasing the capacity of 
the lungs. The purpose of certain gymnastic 
exercises is to increase the lung capacity. This 
is true especially of exercises of the arms and 
shoulders combined with deep breathing. Such 
exercises increase the capacity of the lungs. 
When the lungs are diseased, as in tuberculosis 
and pneumonia, their capacity is diminished, 
and therefore the frequency of breathing is 
increased. 

A grown person in good health, weighing one 
hundred fifty pounds, will generally take about 
a pint of air into his lungs at each breath. 
Children, naturally, take less, and the smaller 
they are the smaller the quantity of air they 
can take in. 

What is the result if a person is deprived of fresh 
air? If a person were confined in a room ten 
feet square and ten feet high, in which there 


20 


HEALTH READER 


was no means of ventilation, the oxygen, which 
is the active agent in maintaining the heat of 
the body, gradually would all be used up. The 
carbon dioxide, which is formed when the food 
and tissues of the body are burned, would be 
constantly increasing in quantity. Suffocation 
and death would finally result, although the 
end would be slow in coming. 

Were it not for the constant replenishing of 
the oxygen by plant life as already explained, 
the air in which we live would after a long inter¬ 
val of time become unfit to breathe. 

QUESTIONS TO HELP THE PUPIL 

i. Into what three classes may the forms of matter be 
classified? 2. How do these classes differ? 3. What do 
you discover by observing a gas that has color? 4. Of 
what gases is air principally made up? 5. How much of 
the air is oxygen? How much nitrogen? 6. How can 
you make carbon dioxide? 7. How is carbon dioxide 
formed in the body? 8. What gas do plants use? What 
gas do they throw out? 9. What gas is necessary for 
the burning of food in the body and for gas flames or 
other fires? 10. When can you see water in the air? 
11. Are there other substances in the air besides oxygen, 
carbon dioxide, and water ? 12. What is the term applied 

to elements composing the air? 13. When is air impure? 
14. How can we tell the air is impure? 15. Can we live 
without air? 16. What happens when a person breathes 
in a room that is not ventilated? 17. What is the value 
of exercises of the arms and shoulders combined with 
deep breathing? 

18. What is breathing ? 19. What do we mean when we 
say that breathing is involuntary? 20. Why is it neces¬ 
sary to breathe ? 21. How much air does a grown person 

take in at each breath? 


III. The Organs of Breathing 

What are the lungs? The lungs are the 
organs of breathing. They are full of little air 
cells and are richly supplied with blood vessels. 
These organs are placed one on the right side 
and one on the left side of the cavity in the 
upper part of the trunk known to scientific 
men as the thorax but commonly called the 
chest. This cavity is formed chiefly by an 
inclosing structure of bones called the ribs. 
Leading to the lungs from the mouth and the 
nostrils is a tube called the trachea , known 
commonly as the windpipe. This tube divides 
into two branches, one going to the right lung 
and one to the left lung. These branches are 
called the bronchial tubes. An inverted tree 
is an excellent illustration of the appearance of 
the windpipe and the bronchial tubes. (Fig., 
p. 22.) The trunk of the tree is the windpipe; 
the roots, the openings into the mouth and 
nostrils. The two main branches are the bron¬ 
chial tubes. These tubes branch out into 
numerous smaller tubes like the smaller limbs 
of a tree. 

The comparison may go still farther. In the 
lungs are numerous small cavities or pockets, 
and these may be compared with the leaves of 


21 


22 


HEALTH READER 


the tree. In fact, the tree absorbs air in a way 
that is a very good illustration of what takes 
place in the lungs, except that the act of breath- 



Lungs, showing larynx , trachea , and bronchial tubes 
A, right lung, exterior; B, left lung, section view; c, larynx; 
d, trachea; e, small bronchial tubes; /, air sacs 


ing goes on in inverse or opposite order. In the 
human body you breathe through the openings 
of the windpipe and distribute to the branches 
and the lung cavities; the tree breathes through 
its leaves and distributes to the branches and the 






THE ORGANS OF BREATHING 


23 


trunk and roots. The human being takes in oxy¬ 
gen and gives off carbon dioxide; the tree takes 
in carbon dioxide and gives off oxygen. Thus 
the comparison is complete but in inverse order. 

The lungs are surrounded by a membrane or 



covering known as the pleura , and are located 
in the cavity inclosed by the ribs. At the back 
of this cavity is the backbone, or spinal column. 
At the bottom is a strong muscular partition 
called the diaphragm. It is by the action of the 








24 


HEALTH READER 


diaphragm and of the muscles contracting and 
expanding the ribs that the capacity of the 
thorax may be increased or diminished. 

By the expansion of these muscles and the 
movement of the diaphragm downward, the 
cavity or box in which the lungs are inclosed is 
increased in size and the air enters through the 
mouth and nostrils to fill this increased cavity. 



By the contraction of the muscles of the ribs 
and the movement of the diaphragm upward, 
the holding capacity of the cavity or thorax 
is diminished and the excess of air in the lungs 
is expelled. Thus breathing is brought about 
by the contraction and expansion of the thorax. 

This can easily be illustrated by a simple 
experiment. If you cover the open top of a 
jar with a piece of rubber and press down on 
the rubber, you will diminish the capacity of the 


l 

































THE ORGANS OF BREATHING 


25 


jar. If you stop pushing and take your hand 
away the rubber will come back to its horizontal 
position and the capacity of the jar will be the 
same as it was at first. If you attach a curved 
tube to the jar and put one end of the tube 
in water you will find that when you push down 
on the rubber cover the air will be forced out 
of the jar through the tube into the water. On 
withdrawing your hand a portion of the water 
will be drawn through the tube into the jar. 
In this way you illustrate the mechanism by 
means of which breathing takes place. 

What happens to the air when it reaches the little 
pockets or cells in the lungs? The cells of the 
lungs are provided with innumerable small 
blood vessels so arranged as to bring the blood 
into all parts of the lungs on its way to and 
from the heart. 

The blood that enters the lungs comes from 
all parts of the body. On its way to the lungs 
the blood stream resembles a river system. 
Small vessels, so small as often to require a 
microscope to discover them, conduct the little 
globules of blood from the tissues in all parts 
of the body and pour them into larger vessels, 
and these into still larger vessels, until they 
reach the veins of the body. Through these 
veins the blood finally finds its way into the great 
blood vessels or tubes that lead to the heart. 
2 


26 


HEALTH READER 


From the heart the blood passes to the lungs 
and is there redistributed through the same 

kind of small 
vessels in which 
)~g it originated. 

These micro¬ 
scopic or very 
small blood 
vessels line the 
walls of the 
lung cells into 
which the air 
particles find 
their way. The 
blood stream is 
loaded with 
water and car¬ 
bon dioxide de¬ 
rived from the 
burning of the 
food and the 
tissues of the 
body in all of 
its parts. When it comes into these little lung 
cells an interchange takes place between the 
oxygen of the air in the lungs and the carbon 
dioxide and the water in the blood. Some of 
the particles of carbon dioxide and water in the 
blood pass through the cell walls into the air 



The heart , showing veins and arteries 
connected with it 

a, right ventricle; b, left ventricle; c, right 
auricle; d, left auricle; e, aorta; /, pulmonary- 
artery; g, branches of the aorta; h, superior 
vena cava; i, pulmonary veins 


THE ORGANS OF BREATHING 


27 


in the cells, and particles of oxygen pass through 
in a contrary direction from the air into the 
blood. In this way each little particle of 
blood is relieved of a load of carbon dioxide 
and water, after which each takes up a load 
of oxygen from the air. At the same time 
it changes color. As the blood, on its return 
from the tissues to the lungs, enters the little 
vessels in the lung cells it has a bluish tint. 
When it passes out it has a red tint. If 
you dress one little girl in a blue dress and 
another little girl in a'red dress, and have the 
little girl in blue carry a lot of blue marbles 
and the little girl in red carry a lot of red 
marbles, and then have them exchange marbles 
and dresses, you will have an illustration of 
what is going on in the lungs. The little girl in 
blue represents the blood in the vessels lining 
the cell walls, and the little girl in red the air 
breathed into the cells. The blue marbles are 
particles of carbon dioxide and water, and the 
red marbles are particles of oxygen. These 
exchanges are continually taking place in the 
lungs like innumerable millions of little girls 
dressed in blue and red exchanging dresses 
and marbles. 

The little blood globules which have thus 
taken on a load of oxygen go to the heart and 
are then sent through the arteries to all the 


28 


HEALTH READER 


tissues of the body. On this journey they give 
up their loads of oxygen and again take on 
loads of carbon dioxide and water, then return 
through the veins on the way to the heart 
and the lungs. This process is constantly 
going on. Every few moments all the blood 
that is in the body passes through the lungs. 
It is also clear that the air that enters the 
lungs bearing its full quantity of oxygen passes 
out of the lungs bearing a full load of carbon 
dioxide and water. 

Can we ever see the water in the air we breathe 

out of our lungs? Yes, it is not an unusual thing 
to see the water in the air we breathe out of our 
lungs. All you have to do is to go out of doors 
on a cold day and blow, and you will see what 
we call the steam or the fog of the breath. The 
cold air condenses the water in the breath and 
forms it into small particles or globules like a fog. 
Another easy way to prove that there is water 
in the breath is to breathe upon a mirror. The 
cold glass will condense the little particles of 
moisture in the breath so that you can see them. 

Is there any way you can see the carbon dioxide 
in the breath? No, not directly. It requires a 
very low temperature to condense carbon diox¬ 
ide. It can be done, however, and the teacher 
of chemistry in the high school may show 
you frozen carbon dioxide. You may see it, 


THE ORGANS OF BREATHING 


29 



however, in an indirect way. If you will breathe 
through a glass tube into a little clear lime water, 
which you can 
easily make 
from a frag¬ 
ment of lime 
or which you 
can buy at 
the drug store, 
you will soon 
see the whole 
mass of water 
become white. 

But these 
little particles 
you see are 
not carbon dioxide. They are particles of car¬ 
bonate of lime, the same thing as limestone or 
marble. This carbonate of lime is formed by the 
union of the carbon dioxide forced out of your 
lungs with the particles of lime in the water. 

What is the practical meaning of these facts? 
This experiment shows you very plainly that 
if you breathe the same air over and over again 
you are continually loading it up with carbon 
dioxide and water. The water is not so very 
bad, because only a certain amount of it can be 
held in the air. Anything over this amount of 
water will be deposited or thrown off. The 


Blowing expired air through limewater 


3o 


HEALTH READER 


carbon dioxide, however, is not deposited. It 
remains in the air indefinitely, and in unlimited 
quantities, and its presence cannot be known 
except in the way described. 

What precautions does nature take to protect 
the lungs? Nature takes many precautions to 
protect the lungs. As we have learned, the 
lungs are covered by a membrane known as 
the pleura. They are located in the thorax or 
chest, a cavity that is entirely closed in by walls 
of bone and muscle. There is no communication 
between the thorax and the external atmosphere, 
although the interior of the lungs is connected 
directly with the outside air through the wind¬ 
pipe. No air can get into the thorax unless 
it leaks in through the lungs or through a punc¬ 
ture in the side walls. The walls of the thorax, 
with the exception of the diaphragm, consist 
of hard, bony materials,—namely, the ribs, the 
backbone, and the sternum or breastbone. This 
cavity therefore cannot collapse, and is able to 
resist the pressure of the atmosphere, which is 
about fifteen pounds on every square inch. 

The walls of the thorax, moreover, are sup¬ 
ported also from the inside. The lungs, being 
porous and expansible or easily stretched, and 
being in communication with the external air 
through the trachea or windpipe and the bron¬ 
chial tubes, are expanded by the air pressure 


THE ORGANS OF BREATHING 31 

until they entirely fill the lung space. The lungs, 
therefore, do not hang loosely in an open space, 
but, in a state 
of health, are 
entirely ex¬ 
panded so 
that their en¬ 
veloping lin¬ 
ing (the pleu¬ 
ra) touches 
the internal 
walls of the 
thorax. Thus, 
by the pres¬ 
sure of the 
air within the 
lungs, the 
walls of the 
thorax are 
supported 
from the inside also, and are prevented from 
yielding under the pressure of the air on the 
outside. 

What causes the diseases that attack the lungs? 

Generally, when disease germs (minute living 
bodies) attack a healthy lung they are over¬ 
come and destroyed by natural enemies which 
nature has put into the blood and thus into 
the lungs. These enemies of the germs are 



The thorax or chest 

a, sternum or breastbone; b, part of 
spinal column; cc, costal cartilages; d, ribs; 
ee, floating ribs 


32 


HEALTH READER 


principally the white corpuscles of the blood. 
For a long time the function of these corpuscles 
was unknown. But it is now known that these 
little white particles, as distinguished from the 
red particles which give the blood its color, are 
police health officers. They are on duty to guard 
against all the thieves and robbers, the disease 
germs which strive to break into the body. 

So long as we are well nourished and are 
living in sanitary surroundings these policemen 
are able to protect us against the bad germs 
which produce disease. On the other hand, 
when we are “run down,” that is, when our 
vitality is lessened, when our food is poor or 
insufficient in quantity or not properly cooked, 
or when it is not properly chewed and digested, 
then we find that the white corpuscles are less 
numerous and are not so vigorous. These 
policemen, in other words, “go to sleep on their 
beats” and the thief and the robber germs enter 
the body and produce infection or cause disease. 

Thus we are apt to have pneumonia when we 
are weakened by a cold, although the particular 
germ which causes the pneumonia is independent 
of the cold. The pneumonia germ is almost 
always present in the mouth, but it does not 
produce pneumonia until the vitality (resistance) 
of the body is lowered. 

Tuberculosis, that most dreaded of all 


THE ORGANS OF BREATHING 


33 


diseases, is produced by a certain germ called 
tubercle bacillus , which enters the lungs through 
the blood or through 
the air. It finds lodg¬ 
ment in the weak or 
less vital parts of the 
lung, grows and in¬ 
creases in numbers, 
and gradually pro¬ 
duces the tubercles 
which absorb, destroy, 
and slowly take the 
place of the lung tis¬ 
sues used in breathing. Tuberculosis kills more 
people than any other single disease. Statistics 
show that out of every one hundred people who 
die, eleven die from this disease. 

How can the diseases which attack the organs of 
breathing be prevented? Diseases can be pre¬ 
vented, first of all by always breathing pure air; 
second, by keeping the body well nourished; 
third, by taking precaution to prevent the spread 
of tuberculosis germs. When there is a case of 
smallpox in a community the patient is taken 
to a special hospital and separated from the 
community until he gets well. But this is not 
always done when there is a case of tuberculosis. 
A patient suffering from tuberculosis walks the 
streets, rides in street cars and railroad trains, 



34 


HEALTH READER 


sits at the table in public restaurants, and in- 
general mingles freely with the public, all the 
while spreading germs which threaten his fellow- 
man. 

The germs of tuberculosis are also present in 
the milk of tuberculous cows. Tuberculosis in 
cows differs somewhat from the tuberculosis 
that attacks human beings. Although the germ 
is different to a certain extent, yet it has been 
proved conclusively that the tuberculosis of 
the cow may be reproduced in human beings, 
and especially in children. The extermination 
of tuberculous cows would do much toward 
diminishing the possibility of spreading tuber¬ 
culosis. 

If we could induce the people who have tuber¬ 
culosis to live by themselves until they are well, 
and if at the same time we could destroy all 
tuberculous cows in the country, we should be 
protected to a great degree against that disease. 
Instead of eleven out of every one hundred 
people dying from tuberculosis we might reduce 
the number greatly. Moreover, if we could 
look forward to days of perfect cleanliness of 
the air and of our food, we might even look 
forward to the day when tuberculosis would be 
completely wiped out. 

Your city and state boards of health would 
gladly undertake to get rid of tuberculosis and 


THE ORGANS OF BREATHING 


35 


all other dreadful diseases, but they do not 
always have the power and the money needed 
to do this. 

The germ of pneumonia exists chiefly in the 
mouth. Therefore the mouth should be care¬ 
fully cleaned at least three times a day, 
occasionally using a tooth paste that will help 
purify and clean the teeth. Rinsing the mouth 
with a sip of dilute hydrogen peroxide, or using 
an antiseptic spray, such as a mixture of odor¬ 
less petroleum, eucalyptus oil, and menthol, will 
also do much to keep this threatening germ out 
of the mouth. In addition to these everyday 
precautions special care should be taken when 
you have a cold to keep the mouth free from 
infection and also to prevent unusual exposure 
to bad weather. At the same time particular 
care should be taken to keep the living-room 
temperature below seventy degrees and the air 
in the room perfectly fresh. With these pre¬ 
cautions, a well-balanced diet, and plenty of 
sleep, you will be able to avoid an attack of 
pneumonia, a disease which kills almost as 
many people as tuberculosis. 

What is the difference between the right lung 
and the left lung? The right lung is not shaped 
exactly like the left lung because of the position 
of the heart, which is placed more to the left 
than to the right side of the thoracic cavity. 


36 HEALTH READER 

The right lung is divided into three parts by 
deep clefts in the lung substances, although 

these parts are 
connected with 
each other so 
as to form one 
single organ. 
These divi¬ 
sions in the 
right lung are 
called the up¬ 
per, the middle, 
and the lower 
lobe. The right 
lung is one or 
two inches 
shorter than 
the left lung 
because of the 
fact that the liver lies just below the diaphragm 
on the right side and pushes the diaphragm up 
against the lung. 

The left lung is smaller and narrower than 
the right lung, but it is longer, and has only 
two divisions, the upper lobe and the lower lobe. 
It is a fortunate thing that the lungs are divided 
into lobes, or parts, by deep clefts. In pneu¬ 
monia, for instance, usually only one of these 
lobes is attacked. If there were no lobes in 



A lobule of a lung 

a, small bronchial tube; bb, air cells; c, lung tissue 






THE ORGANS OF BREATHING 


37 


the lungs an attack of pneumonia might affect 
the whole lung. The physician is always hope¬ 
ful of a recovery if he can confine the pneumonia 
to a single lobe. 

How does a fish breathe? You have been told 
that any one who cuts off the air from his lungs 
by putting his head under water will drown. 
Now, although fish have their heads under 
water most of the time, and though the same 
oxygen that purifies your blood purifies the 
blood of the finny tribe, still they do not drown. 
How then does the fish breathe? 

The water in contact with the air absorbs 
some of the atmosphere, including all of the 
gases. Naturally the water near the surface is 
more nearly saturated with air than the water 
farther down. It is also clear that if the sur¬ 
face of the water is roughened by the wind, or 
splashed in any way, it comes in contact with 
greater quantities of air and absorbs more of it 
than if the surface were quiet. A fish breathes 
by drawing this absorbed air out of the water 
near the surface. 

Some of the animals that live in the water 
come to the surface to breathe above the water. 
The whale, for instance, which is not a fish, 
breathes in a great deal of air and blows it out 
again when it spouts. Some fish jump into the 
air and thus have a chance to breathe the air 


38 


HEALTH READER 


#bove the water. In general, however, fish 
breathe by extracting the oxygen absorbed by 

the water which 
comes in contact 
with the open air. 

The fish, by the 
movements of its 
gills, which are its 
lungs, causes a large 

Head of trout, showing gills quant ity of water to 

pass through and over them. The air contained 
in the water is absorbed into the gills of the fish. 

So, as long as the water contains air, the fish 
is able to keep its head under water. But if 
the water is covered with a sheet of ice, and does 
not come in contact with the air, the air ab¬ 
sorbed in the water will gradually be used up. 
Then the fish will suffocate. You may have 
seen in the spring a pond full of dead fish. 
They have been suffocated because ice entirely 
covered the water during the winter and kept 
them from coming in contact with the air. If 
there is a hole in the ice fish will seek it in great 
numbers, rising to the surface in order to get 
the oxygen that has entered the water. Thus 
we see that fish, if kept in water from which 
the air is excluded, would be suffocated just 
as human beings are suffocated by putting the 
head under water. 





THE ORGANS OF BREATHING 


39 


How does air enter the lungs? The air enters 
the lungs either through the mouth or through 
the nostrils. The nostrils are the natural breath¬ 
ing tubes or pipes and should be used for breath¬ 
ing at all times, except perhaps when one is 
talking or singing. Especially in sleep should 
the breathing be done through the nostrils. 

The tube or canal in each side of the nose 
is not perfectly straight. The air in passing 
through the nostrils thus comes in contact with 
the moist membranes which line them. Par¬ 
ticles of dust and other matter in the air are 
caught and held by the moist walls. They are 
thus prevented from entering the lungs. The 
membrane lining the inside walls of the nostrils 
is moistened by mucus and is called a mucous 
membrane. Thus the air that enters the lungs 
through the nostrils is freer from dust particles 
and is cleaner than that which enters through 
the mouth. 

The cavity of the mouth. The mouth is one 
of the most important parts of the body in 
relation to health. In the mouth are the teeth, 
by means of which the food is masticated. It 
also contains the tongue, which carries the 
nerve of taste. Without our tongues we could 
make noises, but we could not pronounce words. 
The tongue also has important functions besides 
that of speech. By its aid the act of swallowing 


40 


HEALTH READER 


is started. Then, too, the walls of the mouth 
contain the openings of the glands which secrete 

the saliva, so im¬ 
portant in keep¬ 
ing the mouth 
moist and souse¬ 
ful in the chew¬ 
ing and swallow¬ 
ing of food. 

The lower 
part of the 
mouth is hinged 
near the ears and 
is movable. It 
can move up 
and down and 
sideways, thus 
aiding in the 
grinding of the 
food between 
the teeth, which 
act as upper and 
lower millstones. 
Back of the mouth are the tonsils , and farther 
down are the trachea or windpipe, through 
which the air is carried to the bronchial tubes 
and thence into the lungs, and the opening into 
the tube—the esophagus or gullet—through 
which our food is conveyed to the stomach. 



Air passages of head and throat 

a, nasal cavity; b, throat; c, larynx; d, trachea 
or windpipe; e, esophagus; /, tongue; g, hard 
palate; h, soft palate; /.tonsil; j, opening of 
Eustachian tube; k , spinal cord; l, spine; m, vocal 
cords; n, roof of mouth; o, epiglottis; —>, passage 
of air through head to lungs 







THE ORGANS OF BREATHING 


4i 


How does food enter the esophagus, and how does 
air enter the trachea? Why does not the food 
we swallow go into the lungs, and why does not 
the air go into the stomach? The answer to 
these questions is extremely simple. The upper 
part of the trachea or windpipe is called the 
larynx. The opening into the larynx is covered 
by a movable hinged lid called the epiglottis. 
When we are 



about to swallow 
food the epiglot¬ 
tis closes so that 
the food slides 
over the top of 
the windpipe 
without enter¬ 
ing. All of the 
food is thus 
carried to the 
esophagus. 


The epiglottis 

a, epiglottis; b, tongue; c, true vocal cords; 


a, epiglottis; u, tongue; c, true vucai 
d , false vocal cords; e 9 cricoid cartilage 


If by any ac¬ 


cident the epiglottis should remain open and a 
particle of food should enter the larynx, violent 
coughing would result. This is nature’s effort 
to throw out the offending body. If water 
or other liquids that we are drinking should 
enter the larynx there would be similar efforts 
to get rid of them. 

The upper part of the trachea, as we have 


42 


HEALTH READER 


learned, is called the larynx. The larynx is 
composed of a series of cartilages or flexible 
tissues midway between muscle and bone. 
Within it lie the vocal cords, two strong, fibrous 
bands covered by a thin layer of mucous mem¬ 
brane. They are of a light yellow color, very 



A, Larynx, front view 

a, epiglottis; b, thyroid carti¬ 
lage; c, hyoid bone; d, trachea; 
e, cricoid cartilage; /, hyoid 
membrane 



B, Larynx, posterior view 

a, epiglottis; b, false vocal 
cords; c, true vocal co^ds; 
d, trachea; e, cricoid cartilage 


elastic, and so arranged that they may be 
brought close together, or tightened or loosened, 
thus changing the tone of the sound produced. 
These changes are brought about by the numer¬ 
ous muscles in the larynx. If the trachea and 
bronchial tubes represent an inverted tree, then 
the larynx represents the root of the tree. It 





THE ORGANS OF BREATHING 


43 


is of great importance to keep the larynx in a 
healthful condition if the voice is to be preserved. 

The air breathed out from the lungs causes 
the vocal cords to vibrate, thus producing 
sounds. If we had no vocal cords, or if they 
should become useless, we could not utter a 
sound, and the tongue, teeth, and lips would 
be deprived of sound material out of which to 
make words. If the vocal cords become in¬ 
flamed, as in sore throat, they often become 
impaired or useless, and we are hoarse or speech¬ 
less as long as the inflammation continues. 

The cover of the larynx, that is, the epi¬ 
glottis, protects the lungs and at the same time 
prevents any foreign matter from clogging the 
vocal cords. The vocal cords are stretched 
like the strings of a violin. They vibrate as the 
air passes over them, and a sound is produced 
when these vibrations are transmitted through 
the air. If the vocal cords are short and tight 
the voice is high and shrill, tenor or soprano; if 
the vocal cords are long and loose the voice is 
low and deep, bass or contralto. 

What is choking ? Choking is the term applied 
to the condition produced when the larynx or 
trachea is closed to such a degree as to prevent 
air from passing through to the lungs. If you 
grasp your throat tightly with your fingers you 
cause the trachea to collapse. This closes the 


44 


HEALTH READER 


passage through which the air enters the lungs. 
If you keep the trachea shut long enough you 
cause death by strangulation. 

If you should try to swallow a large quantity 
of food at once, so large that it would not pass 
through the esophagus, it would stick in the 
esophagus, bulging it out. As the esophagus 
lies back of the trachea, this bulging out might 
also close the trachea. In such a condition you 
would choke to death. If, on the other hand, 
the food were lodged in the esophagus in such 
a way as not to close the trachea, you might 
not choke to death for a long while, and if the 
obstruction were removed probably no harm 
would result. If the epiglottis were open and 
food should enter the trachea, the food would 
close the opening to the lungs and quickly 
cause death. In a case where speedy death is 
threatened by choking in this manner, the per¬ 
son should be held head down and sharp blows 
given with the palm of the hand on his back. 

The palate. The roof of the mouth is called 
the palate. It is very hard and firm in the 
front part of the mouth. Toward the back of 
the mouth it becomes soft. In the middle of 
the soft palate at the back of the mouth hangs 
a small conical fold, which swings like a pendu¬ 
lum. This fold is known as the uvula. Some¬ 
times the uvula becomes so long that it hangs 


THE ORGANS OF BREATHING 


45 


down and touches the top of the larynx, that 
part of the trachea holding the vocal cords. 
This produces a tickling sensation which in¬ 
duces coughing, and it is thus often troublesome 
to public speakers. In such a case it is a simple 
matter to seize the projecting point with forceps 
and cut off a portion of it. While this is a 
simple matter it should not be done by any but 
a competent surgeon, using sterilized apparatus 
so as to avoid every danger of infection or 
inflammation. 

The tonsils. The tonsils are two glands at 
the back of the mouth which protect the body 
against germs. When the germs are so numer¬ 
ous that the tonsils cannot destroy them all, the 
tonsils become infected, especially in children. 
It is advisable in such cases, especially when the 
tonsils are enlarged, to have them removed by 
a surgeon. 

The pharynx. Back of the mouth is the 
pharynx. This cavity extends upward back of 
the soft palate and is bounded above by the 
lower wall of the framework inclosing the brain, 
and below by the beginning of the esophagus. 
In grown persons it is about four inches long. 
It is a kind of meeting place for various roads. 
The two principal roads opening into the phar¬ 
ynx are the mouth and the nasal passages. But 
there are other paths of very great importance 


46 HEALTH READER 

connected with the pharynx. These are the 
tubes which run from the pharynx to either ear, 

and are known 
as th e Eustachi¬ 
an tubes. They 
lead to the cav¬ 
ity in the ear 
located back of 
the membrane 
on which are 
received the 
sounds from 
the outer air. 
The lower con¬ 
tracted portion 
of the pharynx 
is the begin¬ 
ning of the 
esophagus. 
What are adenoids? Adenoids are an in¬ 
crease in the size of adenoid tissue, which 
exists at the junction of the nasal passages and 
the pharynx. Adenoid growths bleed easily. 
The child that has had adenoids for some time 
has a peculiar expression of the face called “the 
adenoid face.” The mouth is usually kept open 
in breathing and the hearing is often impaired. 
Frequently the hypertrophy (increase in size) 
extends to the tonsils. The only treatment that 



Interior of ear with canals 

a , semi-circular canals; b, cochlea; c, Eustachian 
tube; d, meatus or auditory canal; e, drum mem¬ 
brane;/, concha; g, pinna; h, lobe; i, small bones 
of the ear 


THE ORGANS OF BREATHING 


47- 


is of any value consists in the removal of the 
growths by a surgeon. In very young children 
these growths may be removed by pinching with 
the fingers and thumb. In larger children, a 
sleeping agent (ether) is necessary. When care¬ 
fully done, there is no danger to the child. 
Children should not be allowed to grow up with 
adenoids. These growths are likely to disfigure 
their faces and interfere with normal physical 
and mental growth. 

Precautions to be taken to prevent colds, catarrh, 
and like diseases. The most important thing 
to be considered is public sanitation, that is, 
the keeping of all public places in a cleanly, 
healthful condition. Especially is this true of 
street cars and schoolrooms. There are times 
when children should not be allowed to ride in 
street cars. Those hours of the day when the 
cars are crowded with passengers are the very 
times when children are most likely to be in the 
car on the way to or from school. 

Even if he has to walk a mile or more, it is 
far better for the child to walk to school, and 
have the benefit of the pure air and the easy 
exercise, than it is for him to get into a crowded 
car in which there are not enough ventilating 
flues, and where the windows are often tightly 
closed and the doors opened only for the exit 
and entrance of passengers. The child will be 


48 


HEALTH READER 


better for the walk to and from school. He will 
do better in his studies at school; he will eat 
better, he will sleep better, and he will be 
healthier in every way because of this exercise. 
Above all, he will escape one of the very com¬ 
mon conditions for taking cold. 

All schoolrooms should be properly ventilated 
and the temperature in winter kept at sixty- 
eight degrees or less. When school authorities 
insist upon these conditions and when city 
children no longer ride to school, even though 
the street cars are sanitary and well ventilated, 
few of the pupils will suffer from colds. 

Play and exercise of the right kind are valu¬ 
able in preventing diseases of the respiratory 
or air-breathing organs. The play or exercise 
should not be too violent. It should, however, 
bring into activity all the different parts of the 
body. It is best for children to play in the open 
air, and all kinds of games are beneficial if the 
exertion is not greater than the body can bear. 

Though outdoor play is to be preferred to 
indoor play, the gymnasium should not be neg¬ 
lected. If well ventilated, clean, and free from 
dust, it provides excellent opportunities for exer¬ 
cise when the weather is so bad that one can¬ 
not play out of doors. Outdoor play is for many 
reasons of more benefit than gymnastic exer¬ 
cises. One reason is that gymnastic exercises 


THE ORGANS OF BREATHING 


49 


are usually very severe on a particular set 
of muscles. Unlike outdoor play they do not 
require the use of all the muscles. It must be 
remembered, too, that even in the best venti¬ 
lated rooms the air is not so pure as it is in the 
open. In addition to this, indoor play lacks 
the benefit that is derived from the sunlight. 



Games should be a part of education. Learn¬ 
ing to play properly is quite as important as 
learning other lessons. The most important 
thing of all is to learn the rules of health and 
make them practical by obeying them. In the 
freedom of outdoor play the lungs are filled 
with air naturally and without conscious effort 
on the part of the child. 



HEALTH READER 


Outdoor play does more good than exercises 
given for a special purpose. The mental state 
in outdoor play favors better results than are 


possible in 
indoor play. 
Outdoor ex¬ 
ercise affords 
an excitement 
and an attrac¬ 
tiveness which 
can never be 
equaled by 
anything 
within four 
walls. On the 



A helpful indoor exercise 


whole, then, outdoor play is greatly to be 
preferred to indoor exercise. 

How can play influence the organs within the 
thorax? All kinds of play increase the rapidity 
of the heart’s action, and thus directly affect 
the organs inside the thorax. Since the blood 
runs directly from the heart into the lungs, 
whence it is to be sent back to the heart and 
then distributed throughout the body, there is 
a close relation between the action of the lungs 
and the action of the heart. As the blood 
circulation increases in activity the breathing 
becomes deeper and more frequent. The lungs 
expand and respond at once to the increased 



























THE ORGANS OF BREATHING 


5i 


activity of the circulation. Thus all kinds of 
properly conducted play or exercises are a 
benefit to the lungs and the heart. 

In general, it may be said that exercises in 
which the arms and shoulders are used are 
especially helpful to the heart and lungs. The 
simple exercise of stretching both arms up over 
the head and holding them there for a short 
time may be practiced methodically. Bringing 
the arms down slowly, straight out from the 
shoulders and with fingers clinched so as to 
make the muscles tense, is also very helpful. 
The swinging of the hands backward, at first 
slowly and gently and then more vigorously 
until the backs of the hands touch, is another 
helpful exercise. The circular movement of the 
arms around the shoulder as a pivot, throwing 
the head back and pressing out the throat and 
the top of the chest, is also a good exercise. 
Stooping over and touching the floor with the 
fingers without bending the knees, bending back 
as far as possible, and bending the body to 
each side gently but firmly as far as you can, 
develops the muscles of the ribs and abdomen 
and increases the ability of the organs of breath¬ 
ing to do their duty. In all these exercises 
deep breathing and an occasional holding of the 
breath for a few moments to expand the lungs 
will be of benefit. 


52 


HEALTH READER 


Indoor exercise with dumb-bells is also help¬ 
ful and greatly strengthens the muscles of the 
shoulders, arms, and thorax. The dumb-bells 
used should be light at first, but gradually the 
weight may be increased as the strength of the 
individual permits. Swinging by the hands, 
climbing a rope with the hands and legs, and 
other exercises of like kind increase the breath¬ 
ing capacity. All of these exercises should be 
taken under the direction of a competent direc¬ 
tor, so that they may be effectual and so directed 
as to avoid harmful results. Playgrounds of 
the right kind for the development of a good 
physique, so necessary for efficiency in later life 
work, are quite as important as good schools 
and useful employment, if not more so. 

What causes a cold? Most people think a cold 
is caused by a draft of air. If this were true 
everybody who goes outdoors, except on days 
of calm, would be in danger of taking cold. 
On the contrary, colds are nearly always pro¬ 
duced by remaining in an overheated room in 
a stale atmosphere. If you have become very 
warm from vigorous exercise or work, and then 
sit down to rest where it is cool, your body may 
be cooled so rapidly as to drive the blood from 
the skin and also harm the internal organs. 
Then you have caught a cold. Mere changes 
of temperature, however sudden they may be, 


THE ORGANS OF BREATHING 


S3 


do not cause a cold unless certain cold-causing 
microbes start to grow in the body. 

Can you catch a cold from another person? Yes, 
this is perhaps the most common way we get 
a cold. Somebody with a cold scatters the 
germs abroad and these, when breathed in, 
attack other persons, who then fall ill. 



Sneezing is a source of danger to persons near by 


Why does not everybody who is exposed to such 
infection fall ill? If the body is well nourished, 
if it has been supplied with pure air, if all the 
organs are in good condition and you are very 
healthy, you will be able to resist the cold-causing 
microbes. But if you are run down, poorly nour¬ 
ished, or very tired, your vitality is so low that 
it will not resist the microbes, and you become ill. 

What makes a person who has a cold sneeze? 
Sneezing is a sudden contraction of the muscles 









54 


HEALTH READER 


which control the expelling of air from the 
lungs. By this contraction the air is forced in 
a sudden puff through the nostrils or the mouth. 
The nerve causing this action is affected by an 
irritation in the nostrils or in the throat, and 
the sudden clearing of the air passages, by 
sneezing or coughing, is nature’s way of getting 
rid of the irritation. 

Is sneezing a source of danger to persons near by? 

Yes. In sneezing, the particles ejected from the 
nostrils or the mouth may be thrown to a great 
distance, and these particles may be the carriers 
of infection. Never go near a person with a cold. 
Never kiss anybody who has a cold. If you 
can avoid it, never stand near a person who 
sneezes when he has a cold. To prevent others 
from becoming infected, one should always hold 
a handkerchief over his mouth and nostrils when 
he sneezes. 

Should children with colds go to school? No. 

Children and grown people afflicted with colds 
should not go to school or into any public hall 
where lectures, plays, or religious services are 
carried on. Persons with colds should be kept at 
home, quarantined if necessary, until the danger 
from infection has passed. The air about a per¬ 
son who has a cold necessarily contains a great 
many germs thrown out by coughing and sneez¬ 
ing, and persons near by are in constant danger 


THE ORGANS OF BREATHING 


55 


of breathing the infected matter into their lungs. 
The medical inspector or teacher should stand 
at the schoolroom 
door every day 
and see that no 
person having a 
cold enters the 
schoolroom. 

Are there other 
places where the 
air may carry dan¬ 
ger of infection 
from colds? Yes, 
many. Among 
the more common Spraying the throat for a cold 

places of infection may be mentioned crowded 
cars — especially in winter, when doors and 
windows are closed—churches, theaters, moving- 
picture shows, and public meeting places of all 
kinds where large crowds gather in a small 
space. Children and even grown people often 
contract dangerous diseases in these crowded 
places from, breathing air which carries the 
germs of colds or other diseases. 

Are colds dangerous? No, colds in themselves 
are not as a rule dangerous. But a person 
afflicted with a cold easily contracts a more 
serious disease; indeed, he is much more likely 
to do so than when in good health. Such 





























HEALTH READER 


56 

diseases as the grip, diphtheria, scarlet fever, 
measles, whooping cough, smallpox, and espe¬ 
cially pneumonia, one of the most dreaded of 
all diseases, may follow a severe cold. 

What is good for a cold? Rest, pure air, good 
food, a soothing antiseptic sprayed into the 
nostrils and throat, and proper attention to 
the bowels are helpful in overcoming a cold. 

QUESTIONS TO HELP THE PUPIL 

1. What happens when you breathe the same air over 
and over again? 2. What are the white corpuscles and 
how can we aid them in their work? 3. What care 
should be taken to prevent tuberculosis? 4. What pre¬ 
cautions should we take to prevent pneumonia? 5. Why 
should we breathe through the nose and not the mouth ? 
6. Why is outdoor play beneficial? 7. What should be 
the temperature in all schoolrooms? 8. What exercises 
are good for the organs of breathing? 9. What causes 
a cold? 10. May we catch a cold from other persons? 
11. What is good for a cold? 

12. What are the lungs and in what part of the trunk 
are they placed? 13. What structure of bones incloses 
them ? 14. What is the trachea ? What are the bronchial 

tubes? 15. To what can the lungs be compared? 
16. What is the pleura? 17. How do the ribs and the 
diaphragm move when a person breathes? 18. What is 
brought to the lungs from all parts of the body? 
19. Describe the journey of the blood from the tissues to the 
lung cells. 20. What is the color of the blood when it 
reaches the lung cells? When it passes out? 21. What 
does the blood bring from the tissues to the lung cells? 
What does it carry back? 22. What have you now 
learned is the purpose of breathing? 23 How can we 
show that there is water in the breath? 24. How can 
you show that there is carbon dioxide in the breath? 
25. How are the lungs protected from the pressure of the 


THE ORGANS OF BREATHING 


57 


atmosphere? 26. What is the sternum? 27. Are the 
right and left lungs alike? 28. Can a fish breathe in 
water? Why? 29. What is the purpose of the saliva 
glands opening into the mouth? 30. What is the esoph¬ 
agus? 31. What is the larynx? What keeps food from 
entering the larynx and the trachea? 32. What are the 
vocal cords? 33. How are sounds produced? 34. What 
would happen if food should lodge in the trachea or stick 
in the esophagus? 35. What is the palate? 36. What 
is the uvula? 37. What is the pharynx? 38. What 
opens into the pharynx besides the mouth and the 
nasal passages? 39. What are the Eustachian tubes? 


3 


IV. How Mosquitoes and Flies 
Endanger Health 

Are mosquitoes a menace to health? The 

results from the bites of some kinds of mosqui¬ 
toes may be very serious. The Culex or ordi¬ 
nary mosquito does no special harm, except 
that it raises a lump with an itching sensation 
and withdraws a drop of blood. If you were 
stung by enough mosquitoes you might die from 
loss of blood, yet the ordinary mosquito would 
not leave with you the germs of any disease. 
But in many parts of the country there is one 
species of mosquito that is especially dangerous. 
You have all heard of chills and fever. The 
common name of this disease is malaria. It was 
so called because of the mistaken supposition 
that the chills and fever are caused by bad air. 
That is what the term “ malaria’* means. But 
we know now that it is not bad air nor night 
air that causes malaria. This disease is caused 
by the bite or sting of a mosquito, not the com¬ 
mon kind, but a kind which is widely distributed. 

The mosquito that conveys what is called 
malaria is the Anopheles. When biting or 
stinging, the Anopheles mosquito assumes a 
position quite different from that of the Culex. 
To stick her bill into the back of your hand the 
58 


MOSQUITOES AND FLIES 


59 



The mosquito which 
causes yellow 
fever 


Culex stands up in a decent way and bends her 
head down. The Anopheles, on the contrary, 
seems to stand on her head so 
as to give more punch to her 
entering bill. Then there is the 
Stegomyia , another kind of mos¬ 
quito which does not bother us 
except occasionally in the extreme 
southern part of our country. 

This variety of mosquito carries 
that dreaded disease, yellow fever. 

Neither the Anopheles nor the Stegomyia is 
dangerous in itself, but if an Anopheles stings 
a person who has malaria the germs or parasites 
of malaria are developed in this mosquito and 
are then transmitted to the next person she 
stings. The same is true of the Stegomyia. 
If she stings a person who has the yellow fever 
and then stings another person who has not the 
fever she conveys the yellow fever parasite to 
that person. In this way both malaria and 
yellow fever are spread. 

What is the proper method of protection 
against these diseases? If possible, kill the 
mosquito. If this cannot be done screen your¬ 
self from mosquitoes. In a country where 
mosquitoes abound, no person should sleep in a 
place where windows or sleeping rooms are not 
carefully screened. In the daytime you can 


6o 


HEALTH READER 


usually protect yourself from the mosquito, but 
at night you fall an easy victim to her.' It does 
not cost much to put mosquito netting around 
any place where you are sleeping. The one 
who does not take this precaution is very likely 
to be stung and suffer from the consequences. 

What is the best way to get rid of mosquitoes? 
It is useless to try to kill all the mosquitoes. 
But it is easy to prevent their breeding. There 
should be no pools of water left where mosqui¬ 
toes can lay their eggs and 
have them hatch. If there 
are tubs or barrels of water 
standing about the house 
they should be covered. - 
If there are pools of 
water around the 
grounds these should 



be drained, 
swamps are 
too big to 
drain, the 
mosquitoes 
may be pre¬ 
vented from 
laying and 
hatching eggs 
by pouring a little petroleum or coal oil on the 
water. The coal oil spreads in a thin film over 


Spraying a pool of standing water with 
petroleum 




MOSQUITOES AND FLIES 61 

the surface of the water and prevents the 
development of the mosquito eggs. Large areas, 
as in Cuba and the Panama Canal Zone, have 
been freed from mosquitoes by taking this 
precaution. 

What is good for the bite or sting of a mos¬ 
quito? From his personal experience, Doctor 
Howard, Chief of the Bureau of Entomology, 
says the most effective remedy is moist soap. 
Take the end of a piece of ordinary toilet 
soap, rub it gently over the puncture, and the 
irritation will soon pass away. Others enthu¬ 
siastically recommend household ammonia, alco¬ 
hol, glycerin, or peroxide. Holding the hand 
near a hot lamp chimney has also been found 
to give relief. 

What is the relation of flies to ill health? 

Flies bear a very important relation to health. 
The fly is really the creature of filth. The eggs 
of the fly are laid in manure or filth of some kind, 
where they are hatched into maggots that 
remain in the manure until they pass into their 
pupa or inclosed stage, from which they pres¬ 
ently come out as flies. Flies constantly visit 
every spot where manure or other filthy material 
is to be found. They go from the kitchen and 
dining room, where they are polluting the food, 
to the stables and outhouses to lay their eggs, 
and then back again, bringing impurities to 


62 


HEALTH READER 


the food supplies. It is believed that typhoid 
fever, diphtheria, and other infectious disease 
germs are very commonly carried by flies. 

What is the best way to prevent flies? Clean¬ 
liness about the house, the outhouses, and the 



The life of a house fly 
a, eggs; b, maggot; c, pupa; d, full-grown fly 


barns is the first requisite for success in the 
fight against flies. So, first of all, it is important 
to remove the filth in which the fly lays its 
eggs. It is estimated that one fly will lay one 
hundred twenty eggs. In from one to ten hours 
these eggs hatch into little white maggots. 
And within four or five days a maggot gradually 
turns into a fly. Then in about four days the 
fly is full grown and ready to start out on its 
errand of producing more flies. Thus one fly 
will, in the course of a week or ten days, produce 
one hundred twenty flies. Thus you see in a 





MOSQUITOES AND FLIES 


63 


very little time one fly can boast of a million 
descendants. 

As flies cannot be entirely prevented from 
breeding, the next best thing is to keep them out 
of the house—out of sleeping rooms, kitchen, 
and dining room. This is most easily done by 
screens. The doors leading out of the house 
should have double screens, to prevent the flies 
getting in when the doors are opened. Any fly 
found in a room should be killed immediately. 
The fly swatter is the advance agent of good 
health. “If at first you don’t succeed, swat, 
swat again!” 

QUESTIONS TO HELP THE PUPIL 

1. What three kinds of mosquitoes are there? 2. Do 
ordinary mosquitoes carry disease ? 3. How can we guard 

ourselves against mosquitoes? 4. How did the Americans 
fight mosquitoes in the Panama Canal Zone? 5. What 
is good for the bite of a mosquito? 6. How do flies carry 
disease? 7. What are the best ways to get rid of flies? 
8. What is a fly swatter? Why should we use it dili¬ 
gently ? 


V. Dust in the Air 


What is it we see when a ray of sunlight enters 
a room, making a straight, shining streak? We see 

fine particles of dust which are invisible until 
lighted up by the ray of sunlight. 

Is there usually much dust in the air indoors? 
Yes, there is, and also dust in the air in most 
other places. The 
dust indoors, however, 
is more injurious than 
the dust in the air out¬ 
doors. One should 
live as much as pos¬ 
sible in the open air. 

Does sweeping make 
more dust? No, sweep¬ 
ing does not make dust; 
it only stirs up the 
dust that has gathered 
on the floor and sends 
it flying in the air 

Stirring up dust with a broom again 

What is dust? Dust consists of particles or tiny 
bits of various substances, the particles being 
so fine and so light that when once started in 
motion they float in the air for a long time. 

If you stir up some clay in water all the large 
64 




DUST IN THE AIR 


65 


particles will soon settle at the bottom, but the 
clay dust remains suspended in the water for 
many hours and even for days. In the waters 
of the Missouri River the clay dust never settles. 
They are always muddy. In like manner dust 
particles float a long time in the air. 

Can you get the dust particles out of water? Yes. 
If you mix a little lime water or a weak solu¬ 
tion of alum with muddy water it will become 
clear in a short time. Substances like these 
cause the fine particles of clay suspended in 
the water to come together and form larger 
particles, which sink. Just so dust particles 
cling together and then sink in the air. 

What results from the entrance of dust particles 
into the lungs? The dust particles often stick 
to the moist surface of the lung cells, causing 
irritation and injury. People who continually 
breathe air containing large numbers of carbon 
particles such as are present in the smoke from 
burning soft coal, often have black deposits of 
carbon in their lung tissues. Although it is not 
possible to find an atmosphere entirely free 
from dust, it is important to avoid, as much as 
possible, breathing dust-laden air. 

How does dust get into the air? Dust is sent 
into the air by moving bodies in contact with 
the surface of the earth, especially when the 
ground is dry. A horse, wagon, or motor car 


5 


66 


HEALTH READER 


in motion will cause dust to rise from the 
ground. But the wind probably does more 



to keep the air full of dust than any other 
moving body. It lifts the dust from the earth’s 
surface, and the harder it blows the more 
difficult it is for the particles of dust to fall to 
the ground again. In many parts of the world, 
especially in deserts and dry regions, dust and 
sand storms are much feared. Sand storms 
and snow blizzards are much alike. In each 
case fine particles are carried through the air 
at a high rate of speed, so blinding the traveler 
that often he loses his way. Sand storms 
are common in the deserts, and snow blizzards 
in the northern, central, and western parts of 
the United States. 




DUST IN THE AIR 


67 


How may those who must breathe a very dusty 
atmosphere protect their lungs ? People who work 
in a dusty atmosphere may protect their lungs 
by placing a moist sponge over the nose and 
mouth. In passing through the sponge the 
dust-laden air strikes the moist walls of the 
sponge cells or spaces and the dust particles 
settle and remain there. From time to time the 
sponge may be washed and then it is again ready 
for use. Threshing grain is dusty work, and 
farmers using threshing machines find wearing 
a moist sponge a great protection. Workers in 
cotton mills also find the sponge a protection 



A sand storm in the desert 


against the lint and dust that fill the air in 
factories and mills. 






68 


HEALTH READER 


What care should be taken to lessen the amount 
of dust in houses? Houses should be built with 
smooth walls. Carved or irregular walls and 
ceilings provide places where dust may gather, 
and from which it is easily brushed off and set 
in motion by opening doors and windows and 
by “dusting.” There should be no projections, 
moldings, or corners where dust may gather. 
Such things as mantels, picture frames, and 
clocks should be frequently cleaned with damp 
cloths. The moisture in the cloth takes up 
the dust that has collected without causing it 
to start sailing through the air in the room. 
Floors should be smooth and without cracks. 
There should be no carpets, and rugs should 
be cleaned frequently. J'he best broom is a 



A weaver wearing a sponge to protect his lungs from dust 
















DUST IN THE AIR 


69 


vacuum cleaner. This appliance or household 
aid takes up all dust. Even carpets are harm¬ 



less if frequently cleaned with a vacuum cleaner. 

What is the danger from dust in the house? 
Disease germs are likely to be present in the 
dust, if there have been sick people in the house. 
The germs of tuberculosis, in particular, are 
likely to be present in house dust for some time 
if persons afflicted with this disease live in or 
visit the house. The sputum (spit) containing 
the germs dries rapidly, and the germs float in 
the air like small dust particles. When lodged 
in the cells of the lungs these dry germs, if of 
recent origin, may become active again and 
thus start the disease that causes more than 
one tenth of all deaths. Tuberculosis is 




















70 


HEALTH READER 


sometimes called a “house disease.” If every¬ 
body lived out of doors there would be very 
little tuberculosis. 

Are the germs of tuberculosis spread about in 
any other way than through the air? Yes, tuber¬ 
culosis germs are spread about in many different 
ways. The infection may come from direct 
contact, as in drinking from a cup that has 
been used by some one suffering from the 
disease. It may also be caused by eating food 
from dishes which have just been used by con¬ 
sumptives, or by drinking the milk of tubercu¬ 
lous cows. A person may also get tuberculosis 
from eating the unsterilized meats of tubercu¬ 
lous or infected animals, especially cattle and 
hogs. These are but a few of the things which 
cause infection. 

How can we be protected from these dangers? 

We can best protect ourselves by spending as 
much time as possible in the open air. While 
disease germs may be present in the air currents 
out of doors, because consumptives have been 
spitting in the street or for other reasons, the 
danger of inhaling these germs is comparatively 
slight because of the great quantity of air in 
which they are carried. On the other hand, 
the air indoors is breathed over and over again, 
and even if there were but a few dangerous 
germs in the room, the chance of breathing 


DUST IN THE AIR 


7i 


them in is very great. In addition to spending 
as much time as possible outdoors during the 
day, a good way to prevent this disease is to 
sleep on a porch at night. Children especially 
should sleep in the open, for it is often in infancy 
and childhood that this disease takes hold. The 



A sleeping porch. People who sleep in the open air 
usually are free from disease 


germs that develop into tuberculosis in persons 
who have reached twenty-five or thirty years 
of age often enter the lungs during childhood, 
and their presence is not discovered for many 
years. People who live and sleep indoors, in 
rooms that are poorly ventilated, offer the most 
favorable conditions for the development of 
the disease. 






















72 


HEALTH READER 


Is there any danger in sleeping out of doors? 

As a rule, there is none whatever. In pleasant 
weather one may sleep on the ground with an 
oilcloth blanket under him and a blanket over 
him. If it rains he should, of course, have some 
kind of protection, such as an oilcloth covering, 
to keep him dry. People who live out of doors, 
play out of doors, and sleep out of doors rarely 
have colds or tuberculosis or diseases of the 
throat. 

QUESTIONS TO HELP THE PUPIL 

i. Is there much dust in the air everywhere? 2. Why 
should we live as much as possible in the open air? 
3. What is dust? 4. Do dust particles remain in the 
lungs? What is the result? 5. What is the cause of 
dust in the air? 6. How should persons working in 
a dusty atmosphere protect their lungs? 7. What care 
should be taken to diminish the amount of dust in the 
house? 8. What is the danger of dust ? 9. What is tuber¬ 
culosis sometimes called? 10. In what other ways than 
through the air are the germs of tuberculosis carried 
about? 11. What is the best way to protect ourselves 
from these dangers ? 12. How can we protect ourselves 

from the weather when sleeping out of doors ? 


VI. A Study of Ventilation 

What is ventilation? “Ventilation” is the 
term applied to the circulation of fresh air 
through rooms in which people live, sleep, and 
congregate. In a well-ventilated room the air 
is so frequently or continuously changed as to 
prevent it from becoming stale or contaminated 
and a danger to health. 

Why is ventilation necessary? Air at rest be¬ 
comes stagnant in the same way that water at 
rest becomes stagnant. So it is desirable to 
keep it in constant motion. This may be done 
either by mechanical means—as, for instance, 
by an electric fan—or else by taking advantage 
of the tendency of heated air to rise and thus 
cause movements of the whole air mass. 

Air confined in a room is usually of a different 
temperature from that of the air out of doors. 
It may be warmer or colder. As a rule, air 
indoors tends to be warmer than outdoor air. 
Thus, if a flue opens into the room, the tend¬ 
ency of the confined air is to pass up that 
flue. Then air of a different character will 
enter through various openings, such as the 
cracks under the doors and around the win¬ 
dows, or other ventilating spaces, and take 
the place of the air that has passed up the 


73 


74 


HEALTH READER 


flue. If there is a chimney and fireplace in the 
room the chimney itself becomes a ventilating 
shaft through which the warm air escapes. 

Entering a room in a building which has been 
kept tightly closed, you at once notice the 
difference between the stagnant air of that 
room and the air in rooms where the doors 
and windows are open at all times and the 
air is kept in constant motion. Thus we see 
the first principle of ventilation is to prevent 
the air from becoming stagnant. 

How does the air become contaminated? In a 
room tightly closed, which has in it no source 
of contamination, air would not change in 
character even if it became stagnant. But 
in living rooms, or in rooms where people 
sleep or congregate, the air is constantly 
used in breathing. We have learned that the 
air which is expelled from the lungs is of a 
different character from that which is taken 
into the lungs. Now if we regard the air that 
enters the lungs as pure, then the air that is 
expelled from the lungs is impure. This im¬ 
pure air breathed from the lungs mixes with 
the pure air in the room and gradually the 
whole mass of air about us becomes impure 
or unclean. 

The smaller the room space or the greater 
the number of people gathered therein, the more 


A STUDY OF VENTILATION 


75 


rapidly will the air become impure or harmful. 

If gas jets or oil lamps are burned in a room 
a similar change takes place in the air. The 
flame of the lamp or the gas is fed by the air. 
The air that is used by the flame may be 
regarded as pure, but the air that comes away 
from the flame is impure. Moreover, if there 
are living beings in the room they are constantly 
throwing off impurities into the air. 

Thus the air in a confined space where living 
bodies are present, or where oil lamps or gas 
jets are burning, and where there is no pro¬ 
vision for a rapid change of the air, becomes 
continually more and more impure. Also, if 
cooking is done in a living room, impurities 
rising from the foods being cooked tend to add 
to the impurities in the surrounding air. In 
order to secure the best conditions of health, 
the air in living rooms must be frequently and 
systematically changed. 

What are the best methods of changing the air in 
a room? The influence of fireplaces and chim¬ 
ney flues and of cracks under doors and about 
windows has already been explained. Though 
not intended for that purpose, all these open¬ 
ings promote ventilation. In some dwellings 
and public assembly halls, however, apparatus 
is especially installed for ventilating purposes. 
Ventilating flues are placed in the walls when 


76 


HEALTH READER 



the buildings are constructed. The size of 
the opening into the rooms may usually be 

adjusted by me¬ 
chanical means, 
according to the 
needs of the space 
to be purified. 
These openings 
are generally 
called ‘‘registers.” 
They may admit 
warm air or cold 
air, or they may 
lead off the im- 

Forcing impure air out with registers 

Ventilation is best regulated when mechanical 
ventilating appliances are used. Ventilating 
by mechanical means generally follows two 
methods: One method is to force fresh air 
through pipes into a room by machinery in¬ 
stalled for that purpose, thus forcing the same 
volume of air out of the room. The other 
method is so to connect the ventilating flues 
with a suction fan as to draw or suck the foul 
air away. The ventilating machinery may be 
so arranged as to regulate the temperature also, 
by heating or cooling the air that is forced into 
the room. 

Where no mechanical ventilators are installed 



























































A STUDY OF VENTILATION 


77 


the doors and windows may serve. If the win¬ 
dow is opened from the bottom, a plate of glass 
or a board should 
be used as a screen, 
in order to direct 
the air upward 
into the room and 
not allow it to 
flow straight in at 
the bottom. If 
two windows are 
used for ventilat¬ 
ing purposes one 
should be opened 
at the bottom and 
the other at the 
top. Wire screens 
covered with 
cheesecloth placed 
in open windows 
are an excellent 
means of securing 

Ventilation Ventilating a room with a 

at bottom of window 



QUESTIONS TO HELP THE PUPIL 

i. What does the term “ventilation” mean? 2. When 
is a room well ventilated ? 3. Why is it necessary to change 
the air in living rooms? 4. Why is a burning lamp or gas 
jet in a sleeping room undesirable? 5' What is a “regis¬ 
ter”? 6. What methods are used in mechanical ventila¬ 
tion? 7. How should windows be opened for ventilation ? 





































VII. A Study of Temperature 

What is the most desirable temperature in a 
room? The temperature in a room in which 
work of any kind is carried on should not exceed 
sixty-eight degrees. This is the most favorable 
temperature for the best results and the highest 
efficiency of the worker. 

When the temperature out of doors is below 
sixty-eight degrees the temperature indoors is 
kept up by means of fireplaces, stoves, furnaces, 
hot-water pipes, steam pipes, or by electric 
heating. All of these methods are good if 
properly regulated. 

When the atmosphere outside is warmer than 
sixty-eight degrees there is no method in general 
use for reducing the temperature. The tem¬ 
perature may be reduced indirectly, however, 
by means of awnings which shield the room 
from the heat of the sun and thus tend to keep 
it comparatively cool. In some public halls 
artificial refrigeration is practiced. Air that 
has been cooled by passing over ice or over 
pipes filled with cold brine is forced into the 
room by means of ventilating appliances. This 
adds much to the comfort of the people in the 
hall, but the process is expensive and so it is 
not often used. Only wealthy people can 
78 


A STUDY OF TEMPERATURE 


79 


afford a machine of this kind in their homes. 
In other words, it really costs much more to 
cool the air in summer, with the appliances 
that are now available, than it does to warm 
it in winter. 

However, so far as comfort is concerned, it 
is much more important to heat cold air than 
it is to cool hot air. If the temperature does 
not go above eighty-five or ninety degrees, 
worrying over hot weather causes far more 
discomfort than the hot weather. A natural 
temperature of from seventy to eighty or even 
eighty-five degrees causes no great discomfort 
to most persons. On the other hand, should 
the temperature of a living room fall to fifty or 
forty-five degrees, unless the people in the room 
are wearing very heavy outdoor clothing or are 
tucked in bed under warm blankets and quilts, 
they are extremely uncomfortable. 

The evils of overheating. One of the common 
evils in the United States in cold weather is 
overheating. This custom prevails everywhere 
—in private houses, in schoolrooms, in churches, 
in public offices and theaters, in railway cars 
and street cars, and in fact everywhere that 
people gather. It is not unusual to find the 
temperature of a living room during the winter 
much above seventy degrees, and even as high 
as seventy-five and eighty degrees. This is 


8 o 


HEALTH READER 


true also of schoolrooms, public halls, theaters, 
and offices. Sometimes in railway cars, espe¬ 
cially in sleeping coaches, it is higher even 
than this. 

Within the last few years there has been 
much improvement in this direction, although 
the evils of overheating are still common. A 
person is not only uncomfortable in an over¬ 
heated room, but is in constant danger. Going 
out of doors into the cold air, he quickly be¬ 
comes chilled and in that condition is an easy 
victim of colds, sore throat, bronchitis, and 
pneumonia. If the temperature in our rooms 
during the winter were never higher than sixty- 
eight degrees, there would be much less suffer¬ 
ing from such diseases. 

Why is the temperature kept so high? The prac¬ 
tice of overheating is due to the mistaken notion 
that when indoors we should be very warm, 
especially if the cold outside is severe. The 
practice of keeping rooms too warm is strongly 
established. Many people would object to a 
temperature indoors as low as sixty-eight de¬ 
grees. When there is more than one person 
in a room, as there usually is, they cannot 
always agree as to the most desirable tempera¬ 
ture. One person wants a temperature of 
sixty-eight degrees, another of seventy, while 
others are not content with less than seventy-five 


A STUDY OF TEMPERATURE 81 

or eighty degrees. If there is no established 
regulation, the one who wants the most heat 
usually gets it. 

In public buildings, schools, theaters, public 
halls, churches, street cars, railway cars, and 
similar places, the temperature should be regu¬ 
lated according to a fixed rule. The general 
public, moreover, should be taught to avoid 
the dangers of overheated rooms in the home. 
The living room should never be heated to a 
temperature of eighty degrees. But many 
mothers have never been so taught. 

When the air out of doors is warmer than 
sixty-eight degrees, as it is sometimes early in 
spring and nearly always all through summer 
and a part of autumn, the windows should be 
opened wide, and also the doors, if that will 
help to let the breezes blow through the room. 
When the air is continually changed in that way 
it is surprising how easily we can bear a tem¬ 
perature above sixty-eight degrees. Anyway, 
a temperature that is high because of natural 
conditions, as it is in summer, does not threaten 
health. The air is pure, it is constantly changed, 
and it is not contaminated by the breath of 
people. 

What are the chief obstacles to perfect venti¬ 
lation? The first obstacle is ignorance oi 
the principles on which ventilation is based; 

6 


82 


HEALTH READER 


second, the difficulties and the expense of 
changing the air in living rooms during the 
winter when the cold is intense. It is evident, 
therefore, that many of the evils resulting from 
poor ventilation, especially when they are due 
to cold weather, will continue for a long time 
without effective remedy. In short, one of 
the principal difficulties is the cold of winter. 
When it is cold many people think they cannot 
afford to open the windows in their living 
rooms, and frequently fail to do so in their bed¬ 
rooms, much to their own discomfort and injury. 

What should be the temperature in a bedroom? * 
The temperature in a sleeping room should be 
much lower than that in a living room. In 
fact, the temperature in a sleeping room, except 
in very cold weather, should be the same as that 
out of doors. The windows and even the doors 
should be left wide open. Sleeping rooms, more¬ 
over, should never be heated by artificial means 
except in cases of extreme cold in high northern 
latitudes. Instead, there should be enough bed 
covering to keep the sleeper warm. 

The bed should not be in the living room. 
Unfortunately, very poor people cannot always 
have both a living room and a bedroom. But 
wherever it is possible the bedroom should be 
separate from the living room, and it should 
not be heated above sixty degrees by artificial 


A STUDY OF TEMPERATURE 


83 


means. The outdoor sleeping room or the 
sleeping porch is the ideal place to sleep, though 
it is not possible for everybody to have one. 

When the children now growing up have 
learned the fundamental principles of ventila¬ 
tion, and know what the proper temperature 
of the air should be, a great change will take 
place in the homes of our people. 

Why is air in motion more agreeable than air 
not in motion? Every one has noticed that 
when the air is motionless the high temperature 
of a summer day seems harder to bear than if 
a breeze is blowing, no matter how lightly. 
But the air in motion is not really cooler. It 
is the constant change in the particles of air 
that come in contact with the body that makes 
a person feel refreshed. In all living rooms and 
sleeping rooms it is important to keep the air 
in gentle motion, either by the natural process 
of ventilation or, in very warm weather, by 
means of an electric fan when available. 

QUESTIONS TO HELP THE PUPIL 

1. What has proved to be the most desirable tem¬ 
perature in a room where work is carried on ? 2. By what 

different appliances may a room be heated in winter? 
3. How may a room be kept cool ? 4. What is the danger 

of keeping a high temperature in living rooms in winter? 

5. What should be the temperature in a sleeping room? 

6. Where is the ideal place to sleep? 7. Is air in motion 
.really cooler than air at rest? 


VIII. The Circulation 

What is meant when we say that the blood cir¬ 
culates? In the human body the blood, which 
is the source of life for every part of the body, 
is in constant motion. This motion is produced 
by the action of the heart. The heart sends 
the blood in two general directions. It sends 
the blue blood from the veins into the lungs, 
and there the blue blood is changed into red 
blood. The red blood then flows back into the 
heart, where it is sent to all parts of the body. 
Reaching the small blood vessels in the body, 
called the capillaries , the blood passes through 
them, changing in color from red to blue. It 
then runs back into the veins, passing continu¬ 
ally into larger veins until it reaches the heart. 
Then the process starts all over again: From 
the heart to the lungs, from the lungs back to 
the heart; from the heart to all parts of the 
body, and from all parts of the body back to 
the heart. 

What is the use of blood? The blood is the 
vital current that carries food particles to all 
the tissues of the body, each tissue selecting 
what it requires or needs. One tissue takes up 
material to build bone, another selects material 
for muscle, a third takes up material to build 
84 


THE CIRCULATION 


85 


the hair, a fourth to form the skin, and so on 
through all the tissues of the body. All of these 



The circulation of the blood 

v, valves to and from the heart; arrows indicate direction of circulation 


food materials are taken from the blood stream. 
The blood also carries particles of oxygen to the 
various tissues which, their usefulness at an 
end, are now ready to be destroyed. 









86 


HEALTH READER 


Quite as important as carrying the oxygen 
and the food is the work of the blood in carrying 
off waste material. It takes the waste material 
away from the tissues, and carries it to the 
various organs in the body whose function is 
to separate it and eliminate it from the body. 
These organs are chiefly the skin, the lungs, and 
the kidneys. 

As we already have learned, an important 
function of the blood is to bring the carbon 
dioxide, which is produced by burning food and 
tissues, and water back to the lungs. There a 
large part of the water and some of the carbon 
dioxide leave the blood by passing into the air 
through the thin membranes of the small cells 
in the lungs. At the same time an equivalent 
amount of oxygen passes in the opposite direc¬ 
tion and enters the blood. Thus the blood not 
only carries oxygen to the tissues but carries 
water and carbon dioxide away from the tissues. 

What is true of the human being is also true 
of all animals that have blood. They all have 
the same system of circulation, and for the 
same purpose, with only such variations as the 
different conditions in which they live have 
brought about. The blood may properly be 
called the life of the body. Without its circu¬ 
lation through the body, life would be impos¬ 
sible. Anything that impedes or prevents the 


THE CIRCULATION 


87 


circulation of the blood causes speedy death. 

The red particles of the blood are minute 
disk-like cells, called corpuscles, which have the 
ability to carry oxygen. They play very im¬ 
portant roles in nourishing and vitalizing the 
body. The red particles may thus be regarded 
as the most important constituent of the blood. 



Red corpuscles 


White corpuscles 


Are there any other particles in the blood? Yes, 
there is a very important family of particles in 
the blood, known as the white corpuscles. These 
are somewhat larger than the red corpuscles, 
and much less regular in shape. For a long 
time their particular function was unknown. 
You have already learned that these white par¬ 
ticles are of extreme importance. For they are 
what may be called the policemen, or sentinels 
of the body. They attack any invading germ 
which might cause illness, and drive it away 
or take its life. For this reason the white 
corpuscles are called phagocytes or “cell eaters.” 


88 


HEALTH READER 


If the body is well nourished the white cells 
are vigorous and numerous and are able to 
destroy any harmful organism that may enter 
the blood. If the body is starved or otherwise 
weakened the white corpuscles are less numerous 
and less active. The disease-bearing organisms 
then escape destruction, fasten themselves on 
the organs of the body, and produce the various 
contagious and epidemic diseases from which we 
suffer. Tuberculosis, diphtheria, measles, small¬ 
pox, typhoid fever, and pneumonia are types of 
such diseases. Hence the importance of having 
the blood sound, healthy, and vigorous. 

QUESTIONS TO HELP THE PUPIL 

i. In what condition must the body be in order to 
have vigorous and many phagocytes? 2. What diseases 
can you name that are caused by germs? 

3. Where is the red blood sent by the action of the 
heart? the blue blood? 4. What is the name of the small 
blood vessels in which the blood is changed from blue to 
red in the lungs and red to blue in the tissues? 5. What 
is the motion of the blood called? 6. How is the food 
material distributed to the various kinds of tissue, bone, 
muscle, hair, and so forth? 7. What does the blood carry 
to the tissues of the body? 8. What does it carry away 
from the tissues? 9. What waste material passes out 
of the body by way of the lungs? 10. What happens 
when the. circulation of the blood stops? 11. What is 
the function of the white corpuscles? of the red cor¬ 
puscles? 12. What is another name for white corpuscles? 


IX. A Study of Combustion 



What are the relations of air and fire? There 
can be no fire, as it is commonly understood, 
without air. When we strike a match for the 
purpose of starting a fire, the friction causes 
enough heat to ignite or light the phosphorus on 
the match, a substance which takes fire easily. 
The large quantity of oxygen close to 
the phosphorus on the head of the 
match is liberated, the phosphorus 
burns, and the fire is communicated 
to the wooden stem. When the 
wood of the match begins to burn, 
however, the flame does not get its 
oxygen from the wood. It must 
draw its oxygen from the surround¬ 
ing air. Thus, after 
the flame is started 
by friction it con¬ 
tinues to burn by 
taking oxygen from 
the air. As the little particles of oxygen in the 
air rush into the flame and unite with the wood, 
sufficient heat is generated to start a more rapid 
combustion, and this burning will continue 
until the flame is extinguished or until all the 
89 



A lighted match 


go 


HEALTH READER 


combustible matter in the wood has been burned 
up and only a little carbon remains. 

How does coal burn? Coal burns in exactly 
the same way as wood. But as a rule more 
heat is required to ignite coal than to ignite 
wood. The coal fire, therefore, must have more 
kindling before it ignites, though the principle 
is exactly the same in both cases. The little 



particles of oxygen in the air unite with the coal 
at a high temperature. This produces addi¬ 
tional heat, and thus the combustion is trans¬ 
mitted from particle to particle until all has been 
consumed. Burning is a chemical process. 

What is the element in wood and coal that helps 
to make the flame and the heat? When wood and 






A STUDY OF COMBUSTION 


9i 


coal are burned, oxygen unites with a substance 
called carbon. You are familiar with carbon 
in many of its forms. When your lamp smokes 
it turns the chimney black with a coating of 
carbon. Carbon is present in large quantities 
in coal. It is also present in charcoal, a material 
produced by burning wood and limiting the 
amount of oxygen so that the wood will not 
be entirely consumed. A diamond is pure 



Section of a charcoal furnace, showing arrangement 
of wood for burning 


crystallized carbon. So-called “lead” pencils 
are made of graphite or “writing stone,” which 
is another form of carbon. 

What substances are produced when wood and 
coal are burned? The burning of wood, coal, 
gas, and oil produces practically the same sub¬ 
stances as are created by the burning of foods 
and tissues in the body. The gases that are 
formed consist principally of carbon dioxide 













92 


HEALTH READER 


and water. The oxygen in the air unites with 
the carbon and hydrogen in these various 
materials—wood, coal, food, and body tissues 
— and carbon dioxide and water are the results 
of the combustion. 

Thus the principal products of combustion, 
whether in a fireplace, in a stove, in a furnace, 
in a lamp, in an engine, in an automobile, or in 
the human body, are carbon dioxide and water. 
The water is gaseous at the time of its produc¬ 
tion, because of the high temperature, but when 
it passes into the air it readily cools and, if the 
air is nearly saturated with it, fogs and drops 
of water will form. The carbon dioxide passes 
into the air just as it does from the lungs, and 
immediately mixes with the air. The amount 
of this gas present in open air is not great. 
The proportion of carbon dioxide in the air is 
about four parts in ten thousand, and remains 
almost the same, except in the neighborhood of 
large cities and factories. 

QUESTIONS TO HELP THE PUPIL 

i. Can there be fire without air? 2. What gas present 
in the air is necessary for combustion? 3. What gases 
are formed by burning? 4. What is the proportion of 
carbon dioxide in the air? 

5. What gases pass out of the lungs in breathing? 
6. What then is the process that goes on in the blood and 
in the tissues of the body? 


X. The Temperature of the Body 

What is the relation of the heat of the body to 
health? The temperature or heat of the human 
body when in a state of health is practically 
unchanging. It is about ninety-eight and a half 
degrees. The heat of the body is maintained by 
the union of the oxygen in the air which enters 
the body by way of the lungs with combustible 
matters — the foods and tissues — in the blood 
and in the 
capillaries. 

Our usual 
idea of com¬ 
bustion is a 
burning with 
a flame or a 
visible glow. 

Any process 
by means of 
which oxy¬ 
gen combines 
with organic 
matter and 
produces heat 
is combustion. 

We usually think of fire in connection with 
a stove or a fireplace or a furnace. But the 



93 

















94 


HEALTH READER 


flameless fires which warm the human body are 
in the blood and in the minute blood vessels or 
capillaries of the body. 

Although the lungs are the organs which take 
up oxygen, the combustion which heats the body 
does not take place in the lungs. The lungs 
simply provide a means of starting the oxygen 



taken up from the air on its way to the various 
parts of the body where the burning takes place. 
The fires that burn in the body have no visible 
signs of flame or fuel. The lungs produce heat 
only in proportion to their weight compared to 
the rest of the body. 

How is the heat of the body kept constant and 
normal? The normal temperature of the body 
























THE TEMPERATURE OF THE BODY 


95 


is about ninety-eight and a half degrees. This 
is the temperature at which the functions of 
human life are carried on to best advantage. 
If the temperature rises above that point we 
have a fever; if it falls below it we are at the 
point of collapse. Thus nature must keep the 
body at a constant, even temperature, and this 
is accomplished by various means. 

In most parts of the world and at almost all 
hours of the day the body is warmer than the 
air. Therefore heat is constantly passing from 
the body to the air. Thus radiation from 
the surface of the body disposes of part of the 
excess heat in the body. 

Large quantities of heat are also carried out 
of the body in the air breathed out of the 
lungs. The air enters the lungs, say at a tem¬ 
perature of sixty-eight degrees. It leaves the 
lungs at a temperature of about ninety-eight 
and a half degrees. Thus a large quantity of 
heat leaves the body by way of the lungs. 

The pores of the skin, also, are constantly 
exuding or discharging water known as perspi¬ 
ration or sweat. This water also carries off a 
large quantity of heat. As it comes to the 
surface of the body it evaporates, absorbing a 
great deal of heat and thus cooling the surface 
of the body. The drier the atmosphere, the 
more rapidly the water evaporates. In very 


p6 


HEALTH READER 


dry climates temperatures of one hundred ten 
or one hundred fifteen in the shade are endured 
without much discomfort because the rapid 
evaporation of the sweat keeps the surface of 
the body cool. When we work very hard, or the 
air is very warm or is saturated with the vapor 
of water, the sweat gathers in drops and often 
runs off the body like raindrops from the clouds. 

Thus the lungs and the skin play almost 
equal parts in providing for the distribution and 
sending out into surrounding space of the surplus 
heat caused by the regular activities of life. 

And while nature burns a great deal more 
material than is necessary to keep the body 
warm enough, it has so arranged matters that 
the inner temperature remains practically the 
same all the time. The activity of all the organs 
thus remains normal, and health is maintained. 

Other factors must also be considered in 
this connection. The building of houses, the 
wearing of clothing, and the custom of heating 
the air in which we live, all tend to maintain 
an even temperature in the body. 

What rule should govern the wearing of clothing? 
For the purpose of keeping the body warm, 
clothing should be adapted to the season of the 
year. Heavier garments should be worn in cold 
weather, and lighter clothing in warm weather. 
Clothing, however, should always be as light 


THE TEMPERATURE OF THE BODY 


97 


as possible, though heavy enough to secure 
the desired result. Too much clothing is very 



injurious,' especially to children. Too much 
clothing hinders the work of grown people, 
reduces efficiency, and in order to get rid of 
the excess of temperature throws upon the ex¬ 
cretory or expelling organs of the body a larger 
burden than they ought to bear. 

In very cold weather, if you must remain 
indoors most of the time, it is wise not to 
wear too heavy underclothing. It is far better 
to have extra wraps, overcoats, and cloaks to 
put on when you go out and to lay aside when 
you again go indoors. In most houses the tem¬ 
perature in winter is kept as high as, and some¬ 
times higher than, in summer. Although the 










9 8 


HEALTH READER 


temperature of the living room should be kept 
practically at sixty-eight degrees, it is a very 
common thing to have it much higher, espe¬ 
cially in schoolrooms, public halls, and churches, 
as well as in offices. A great many people spend 
their winters in rooms heated to above seventy 
degrees and sometimes as high even as eighty 
degrees. At the same time they wear heavy 
winter clothing. Such practices cause serious 
injury to health. 

It is better not to wear heavy underclothing, 
even in winter. If you go out of doors and are 
not engaged in active work, overcoats and cloaks 
and wraps will keep you warm. If you are 
engaged in active work out of doors, you will 
not need nearly so much clothing, and as it is 
usually necessary to go indoors from time to 
time, heavy clothing is a burden. Thus it is a 
mistake to wear heavy underclothing in winter. 
The danger is especially great in the spring, 
when the heavy clothing is changed for lighter 
and the weather suddenly becomes cold again. 
In order to avoid this danger the safest plan is 
to wear as little clothing as you can to protect 
you from the cold. 

In what other ways may we control the heat of 
the body? The character of the food we eat 
is highly important in this connection. This 
point will be treated fully in another part of the 


THE TEMPERATURE OF THE BODY 99 


book. It is sufficient now to say that the fats, 
especially, are the heating foods. A certain 
quantity of fat produces as much heat, when 
burned in the body, as two and a quarter times 
that quantity of sugar or starch, and more than 
twice as much heat as the same weight of a 
nitrogenous body, such as lean meat, the white 
of an egg, or casein of milk. In cold weather, 
therefore, we should eat more fat and in warm 
weather less fat. Meats and oils, the foods 
that contain fat, while splendid foods for win¬ 
ter, should be eaten only in small quantities in 
summer. The importance of thus controlling 
the temperature is not fully appreciated by 
most persons. 

What causes a fever? A disordered condition 
of the body causes a more rapid burning up of 
materials in the body than a normal state of 
health. The result is an amount of heat which 
cannot be controlled or expelled rapidly enough 
to prevent a rise of temperature, and we have 
what we call a fever. 

The fact that we have a fever always indicates 
some disordered condition of the body which 
may or may not be of a serious character. A 
rise of temperature of even one degree is the 
signal that the body has passed from a state 
of health to a state of ill health. It is true that 
in a state of health the normal temperature may 


100 


HEALTH READER 


vary almost as much as one degree during the 
day, there being daily variations, as well as 
variations at longer intervals. There is always 
a slight increase in temperature after violent 
exercise or after eating a hearty meal, or per¬ 
haps as the result of some undue excitement. 
Such increases, however, are not sufficient to 
cause disorder in the functions of the organs, 
and do no harm. 

As a rule, nature’s first signal that something 
is wrong is a variation in the heat of the body. 
On a railway train, when the oil is not properly 
transmitted to the axle, we have a hot box. 
In other words, the car axle has a fever. 

How high does the temperature rise in case of 
sickness? In a light fever the temperature of 
the body is from one to two degrees higher 
than normal. When the fever is severe the 
temperature reaches one hundred three or one 
hundred four degrees, or four and a half to 
five and a half degrees higher than normal. If 
the temperature rises above one hundred five 
degrees it is an indication that the patient is in 
a very serious condition. In very severe cases 
of fever, as in typhoid, the temperature some¬ 
times reaches one hundred five and even one 
hundred six degrees, and yet the patient will 
recover. Such high temperatures, however, are 
usually a sign of approaching death. 


THE TEMPERATURE OF THE BODY ioi 


How may the temperature of the body be meas¬ 
ured? The temperature of a sick person is 
measured by means of an instrument known as a 
clinical thermometer. The clinical ther¬ 
mometer is a small, carefully constructed 
thermometer, so adjusted as to register 
temperatures from ninety to one hundred 
ten degrees. Generally the bulb of the 
thermometer is placed under the tongue 
and the mouth is tightly closed. The 
clinical thermometer is so delicately ad¬ 
justed that within one or two minutes 
after it is placed in the mouth it will 
register accurately the maximum temper¬ 
ature of the mouth. The column of 
mercury is also so adjusted that it will 
remain at the highest point. Thus it 
may be read at leisure, and an accurate 
record secured. 

What are some of the principal evils of Cl ^ r c . al 
overheating? Overheating, if it is not ex- mometer 
cessive, does not as a rule produce any great in¬ 
crease of temperature in the body, for the reason 
that the healthy body is able to eliminate the ex¬ 
cessive heat. Overheating and too much cloth¬ 
ing are common causes of ill health and suffering. 
Children and especially infants are injured, for 
the tendency of careful mothers is to bundle 
them up with entirely too much clothing. While 










102 


HEALTH READER 


it is true that an infant should be carefully 
protected from the cold in the first days of its 
life, it is soon strong enough to bear a cool 



atmosphere without a large amount of wraps. 

There should be only enough bed clothing to 
keep a person warm. If his digestive functions 
are in good condition a healthy person can 
sleep comfortably in a very low temperature 
without a large quantity of bed clothing. At 
certain times in northern climates the tem¬ 
perature falls very low. Then we need more 
clothing for outdoor use and for the bed. 

Mothers should never wrap warm clothing 
around the necks of their children. The per¬ 
son who wears fur collars, comforters, and such 




THE TEMPERATURE OF THE BODY 103 

things around the neck catches cold very easily. 
The health of the child should never be sacrificed 
to prevailing styles, if these require such things. 
Children’s clothing should be so made as to 
leave the neck bare. In this way they are much 
more likely to go through the winter without 
colds. 

The keeping of an even temperature in the 
body is one of the fundamental conditions of 
health. If we desire to aid nature we must 
be careful in regard to our eating, in regard to 
the temperature of the rooms in which we live 
and of those in which we work, and in regard 
to the kind and amount of clothing we wear. 

QUESTIONS TO HELP THE PUPIL 

1. What is the temperature of the body when in a 
state of health? 2. How is the heat of the body main¬ 
tained? 3. What is the difference between combustion 
in the body and a real fire? 4. How does the body get 
rid of excess heat? 5. How do the lungs send off the 
heat? 6. How do the pores of the skin keep the body 
cool? When are the pores most active? 7. What rule 
should be observed in the wearing of clothing? 8. What 
is the effect of too heavy clothing? 9. Does the kind of 
food we eat influence the heat of the body? 10. What 
is a heating food? 11. When should we eat less fat? 

12. Does the temperature of the body change in sickness ? 

13. If the temperature rises what do we say the person 
has? 14. How high may the temperature rise in case of 
fever? 15. How may the temperature be measured? 

16. What is one of the fundamental conditions of health? 

17. Of what things must we be careful in order to keep 
an even temperature in the body? 


XI. The Skin and Its Functions 


What are the functions of the skin? The skin 
is the protective covering of the body. It is an 
important organ of the body. It plays a leading 
part in the maintenance of an even temperature 
in the body. It serves to protect the more 
tender tissues lying under it, and to take care 
of certain excretions or waste products which 
are necessary to health and life. 

One of the chief functions of the skin is to 
give us the sense of touch. Innumerable 
nerves or nervelets connected with the larger 
nerves and the nerve centers of the body end 
in the skin. We feel through the skin. The 
nerves in the skin carry the sensation of touch 
to the nerve centers and to the brain. We 
can tell by touch whether things are hard or 
soft, hot or cold. Thus to a great extent it 
is through the skin that we become acquainted * 
with the outside world. Blind people, through 
their sense of touch, read with their fingers. 

What is the structure of the skin? The outer 
layer of the skin is called the cuticle or epidermis. 
This tough, outer layer is constantly being 
rubbed off, while materials for a new outer 
layer form under it. The cuticle carries neither 
nerve filaments nor blood vessels; hence it may 


104 



THE SKIN AND ITS FUNCTIONS 105 

be removed without pain and without causing 
any blood to flow. 

If any part of the cuticle is rubbed continu¬ 
ally, it grows more rapidly and becomes hard 
and thick. If you examine the hands of a man 
who does rough work, you will find the skin 
comparatively hard, tough, and thick. The 
cuticle on the sole of the foot is much thicker 
and harder'than it is on the top of the foot. 
When boys go barefoot the cuticle on the soles 
of their feet thickens and hardens. If a person 
wears tight or ill-fitting shoes that rub on the 
skin over a joint, the cuticle becomes thickened 
and hardened and the result is what is called a 
corn. This hardening of the skin is nature’s 
effort to give added protection to the parts that 
are being rubbed. 

Underneath the cuticle is the cutis vera or true 
skin. On the surface of the true skin are spread 
the little projections which hold the terminals 
of the sensory nerves or the nerves by which 
one feels. Here also are the sweat glands, the 
roots of the hair, and the oil or fat glands. In 
addition to the protection which the skin pro¬ 
vides as a covering for the body, other means 
of protection are provided by nature—for in¬ 
stance, the hair, and the nails on the fingers 
and toes. The nails and the hair are really 
skin tissues with special modifications according 


io6 


HEALTH READER 


to the needs of the body. There is no better 
protection for the head from the heat of the 

sun and the 
cold of the 
winter than a 
a thick cover¬ 
ing of hair. 
The skin 
^ of the whole 
body is cov- 
ered with 
hairs. They 

are usually 
>c 

very small, 
but they can 
easily be seen 
either with 
the naked eye 
or by means of a magnifying glass. Each hair 
grows up through the skin much as a seed grows 
up through the soil. The hair does not conduct 
heat or cold, and therefore a covering of hair 
or fur is one of the best protections against 
changes of temperature. Animals that live in 
cold climates have heavy fur. This fur is a 
protection against both the heat of the sun in 
summer and the cold of winter. 

How does the skin perform the function of regu¬ 
lating temperature? We have already learned 



The structure of the skin 

a, epidermis; b, cutis vera; c, fatty tissue; d, papillae; 
e, hair; /, oil glands; g, duct of sweat gland; 
h, sweat gland; i, papilla of hair 




THE SKIN AND ITS FUNCTIONS 107 

that the heat of the body is influenced not only 
by the thick covering the skin provides but also 
by the sweat glands in the skin. The sweat 
glands eject certain watery secretions from the 
body. But sweat is not pure water. Sweat 
contains other substances in solution, among 
them considerable quantities of common salt. 
Sweat glands are present in all parts of the 
true skin, though not in the cuticle. They 
are usually surrounded by particles of fat. 
This fat keeps the sweat glands pliable and 
assists them in their important work. Each 
one of these glands has a very small duct or 
tube which leads spirally, that is in a winding 
way, through the true skin and the cuticle. 
The opening is not even with the surface of the 
skin, but is oblique, in order to be more easily 
kept from becoming clogged by substances 
clinging to the surface of the cuticle. These 
ducts are larger and more numerous in the skin 
in those parts of the body that are most active 
in sweating, as, for instance, in the skin of the 
forehead and the arm pits. It is estimated 
that on the palm of the hand there are about 
three thousand of these openings to each square 
inch of surface. 

We have already learned that one of the two 
principal products of combustion in the body is 
water, the other being carbon dioxide. Much 


io8 


HEALTH READER 


of this water is excreted or thrown off through 
the sweat glands, while the carbon dioxide is 
almost entirely excreted through the lungs. 

Is cleanliness of importance to health? The 
skin may be regarded as a machine. As in the 
case of other machines, its efficiency may be 
maintained only by close attention and care. 
If a watch is to be kept running accurately it 
must be taken apart from time to time and 
thoroughly cleaned. The watch, in other words, 
must have a bath. 

The surface of the skin is constantly exposed to 
disease or infection from its own excretions, and 
from those substances which may be deposited 
on it from the atmosphere and from the objects 

with which it 
comes in con¬ 
tact. Hence 
frequent cleans¬ 
ing of the skin 
is necessary. 
Careful boys 
and girls will 
wash their 
hands several 
. . , , 7 times a day 

A corner m an up-lo-date bathroom . J 

and their faces 

at least once. Although most of the body 
is protected by clothing from the harmful 
























































THE SKIN AND ITS FUNCTIONS 


iog 

substances in the air, it is much more likely 
to be harmed by excretions of the body than 
are the hands 
and the face. 

Hence the 
whole body 
needs to be 
bathed fre¬ 
quently and 
thoroughly. 

Whenever 
conditions A swimming pool 

allow—and conditions are rarely ever so un¬ 
favorable as to prevent—the bath should be 
taken daily. The bath is most refreshing and 
of greatest benefit if followed by vigorous rub¬ 
bing and kneading of the body. 

What should be the temperature of the bath? 
As a rule the temperature of the bath should be 
as nearly as possible the same as that of the 
living room. About sixty-eight degrees is the 
ideal temperature for the morning bath. It 
may safely be a little lower or a little higher, 
according to the different seasons. A hot bath 
with soap is to be preferred for cleansing pur¬ 
poses to the cool bath with pure water. A 
cool bath with pure water and a little soap, 
however, if taken daily, will keep the body 
clean, even if the temperature of the water is 
















no 


HEALTH READER 


no higher than seventy degrees. For young 
children and infants the temperature of the 
bath should be about the same as that of the 
body. Very young infants should be bathed 
in water not under ninety degrees in tem¬ 
perature; children of from one to two years in 
water not under eighty degrees. For children 
over three or four years of age, the standard tem¬ 
perature of sixty-eight or seventy degrees is best. 

Since the skin is a very important organ in 
regulating the temperature of the body and 
keeping it at the normal, and has many other 
important functions, it should be given the 
greatest care that it may remain healthy and 
in the best condition. 

QUESTIONS TO HELP THE PUPIL 

i. Why is frequent cleansing of the skin desirable? 

2. What makes the bath most refreshing and beneficial? 

3. What is the best temperature for the bath for children 
from one to two years old? over three or four years? 

4. What are the chief functions of the skin? 5. What 
is the outer layer of skin called? 6. What happens to 
the epidermis when it is rubbed continually? 7. What 
is the name given to the true skin? 8. What organs are 
located in the cutis veraf 9. What modified forms of skin 
tissue are provided for the body’s protection? 10. Why 
is hair a protection against changes of temperature? 
11. What is the function of the sweat glands? 12. What 
is the purpose of the fat or oil surrounding them? 
13. Why are the openings of the sweat glands placed 
obliquely? 14. About how many sweat glands are there 
to a square inch on the palm of the hand ? 15. What prod¬ 
uct of combustion is thrown off through the sweat glands? 


XII. Water and Its Function in Health 

What is water? We have seen how the oxygen 
of the air unites with the hydrogen and carbon 
of the foods and of the tissues and produces 
water and carbon dioxide. Attention has also 
been called to the fact that if we place a piece 
of wood or coal on the fire, and it burns, much 
the same kind of “smoke” is produced as that 
which arises in the human body. In other 
words, the greater part of the “smoke” that 
goes up the chimney or comes out of the lungs is 
composed of carbon dioxide and water. When 
carbon dioxide and water are in the form of gas 
they are not visible. In the smoke that goes up 
the chimney the carbon dioxide and water are 
not visible; the smoke we see consists chiefly of 
such impurities as unburned carbon. Neither 
do we see the “smoke” that comes out of the 
lungs unless the air into which it is breathed is 
cold. The cold condenses the moisture and it 
then becomes visible. This also happens if we 
breathe on a cold polished surface, like glass 
or metal. 

What is the chemical composition of water? 

Water is composed of two substances, known as 
hydrogen and oxygen. We have learned that 
oxygen is an important part of the mixture we 


hi 


11 2 


HEALTH READER 


call air. But hydrogen is not present in the 
atmosphere under ordinary conditions. 

Thus the air we breathe into our lungs may 
be said to contain no hydrogen except that in 
the watery vapor which is always present in 
the air. 

What are some of the chief properties of water? 

We are so familiar with water that we scarcely 
ever think of trying to describe it. Water 
produces the condition we call wet. We are 
perfectly familiar with that condition. If we 
stand out in a rainstorm a little while our 
clothes are wet through and through. 

Water also has the power of dissolving sub¬ 
stances. If you put a piece of sugar in water 
it begins to dissolve rapidly: If you stir the 
water it will dissolve more rapidly. If you 
place the lump of sugar in a spoon and hold it 
just below the surface of the water it dissolves 
as rapidly as if the water had been stirred. 
If you make this experiment in a glass vessel, 
and hold it up to the light, you will see the 
melted sugar flowing down in currents through 
the water, although it is perfectly colorless. 
The sugar solution flows to the bottom because 
it is heavier than the water. It thus makes 
room at the top for the water that has less sugar 
in it, and the solution of the lump of sugar goes 
on with greater rapidity. If you put a lump 


FUNCTION OF WATER IN HEALTH 113 

of salt in the water the same thing will occur, 
but more slowly. Thus we say that sugar is 
more soluble in water than salt. 

Does the temperature of water affect its power 
to dissolve substances? Yes, very markedly. 
As a rule hot water dissolves a greater amount 
of a substance than cold water, and does it 
more rapidly. In the case of common salt, 
however, the reverse is true. Cold water will 
dissolve salt more rapidly and in greater quan¬ 
tity than hot water. 

Water dissolves almost everything with which 
it comes in contact. Thus the water that runs 
down through the rocks underground and flows 
out again in a spring will carry in solution 
traces of the rocks with which it has come 
in contact. If iron ores are present in the 
rocks the water will carry away traces of iron. 
If there is marble or limestone in the path of 
the water through the earth it will dissolve 
large quantities of these substances. And so 
with almost every other known substance. 
But there are a few substances that are ex¬ 
tremely insoluble in water—for instance, metals 
such as gold, silver, and platinum, though under 
certain favorable conditions even tiny bits of 
these substances may be found in water which 
flows through rocks. Water has been very 
properly called the “universal solvent.” 


HEALTH READER 


114 

What effect has heat on the volume of water? 

Heat affects water, as it does most other sub¬ 
stances, by increasing the volume or amount. 
To prove this, fill a vessel with cold water and 
in the mouth of the vessel place a cork with a 
glass tube through it. Then set the vessel 
over the fire, and you will see the liquid mount 
rapidly in the tube. The water is expanded 
by the heat and is forced into the tube. The 
expansion continues until the water begins to 
boil. 

How much water is there in the human body? 

The human body is practically three fourths 
water. The food we eat contains about the 
same relative amount of water as does the 
human body, that is, seventy-five per cent. 
Some foods contain a great deal more water. 
Milk, for instance, contains eighty-seven per 
cent. The cereals, on the other hand, when 
uncooked, contain only about twelve per cent. 
Refined sugar contains practically no water. 
But as a whole the proportion of water in our 
food is about seventy-five per cent. 

How much water should we drink? This is de¬ 
termined largely by the feeling of thirst or desire 
for water. Thirst is nature’s best way of telling 
us, through the nerves, that the body is demand¬ 
ing a larger supply of water. Thirst may be 
produced in many ways. If we eat a great deal 


FUNCTION OF WATER IN HEALTH 115 

of salt or sugar, both of which require a con¬ 
siderable quantity of water to dissolve them, 
more or less water is drawn from the tissues 
with which these articles come in contact. This 
taking away of the water, usually from that in 
the stomach, produces a sense of thirst, which 
we gratify by drinking water. 

The sense of thirst is also usual in hot 
weather, because so much water is discharged 
from the body in the form of perspiration. If 
we play or work hard on a hot day we speedily 
become thirsty, for the quantity of water in 
the body is distinctly reduced by perspiration. 
A very slight decrease in the quantity of water 
in the tissues will produce a sense of thirst. 

Those who drink alcoholic beverages in con¬ 
siderable quantities also become thirsty. This 
is nature’s way of telling us that these poisonous 
liquids should be diluted or weakened as much 
as possible. Like salt and sugar, alcohol also 
extracts or draws water from the tissues with 
which it comes in contact. 

There are many other things that cause 
thirst. Dry foods or overeating, especially of 
meats and highly seasoned foods, is a cause of 
thirst. A fever, or a bodily temperature higher 
than the normal, usually makes us thirsty. 

Thus we see that thirst may be a normal 
condition, caused by physical exertion, hot 


n6 ' HEALTH READER 

weather, or eating dry foods. It may also be 
an abnormal or unusual condition, as when it 
is caused by taking large quantities of salt, 
sugar, candy, meats, highly seasoned foods, and 
alcoholic beverages, or when a person is ill with 
a fever. But whether the thirst is normal or 
abnormal the best plan is to drink water. 

Is there any other method of quenching thirst 
besides drinking water? All kinds of beverages 

are used for 
the purpose 
of quench¬ 
ing thirst. 
Among them 
are the so- 
called “soft 
drinks.” 
These drinks 
are made 
principally of 
sugar, cara¬ 
mel or burnt 
sugar, some 
aromatic or 

At the soda water fountain & bitter prin _ 

ciple like extract of bitter almond, and water. 
They are usually very sweet, and are poor bev¬ 
erages for quenching thirst. Drinks to which 
substances such as caffeine, found in coffee, or 








FUNCTION OF WATER IN HEALTH 117 

cocaine, found in the coca leaf, have been added 
are also supposed to quench thirst. Coca Cola 
is a type of soft drink containing caffeine. 
Moreover the drinks containing alkaloids are 
harmful. Tea and coffee are said to quench 
thirst. Lemonade and orangeade and soda 
water are sold in large quantities to satisfy 
thirst. B.ut none of these so well answers the 
purpose as pure water of the right temperature. 

What should be the temperature of drinking 
water? Unfortunately, it is the custom in the 
United States to use drinking water that has 
been reduced almost to the temperature of 
melting ice. It is common, especially in sum¬ 
mer, to place ice in the drinking water. This 
is a harmful practice. Drinking water should 
be kept at a temperature not lower than fifty 
degrees and not higher than the temperature of 
the body. At those temperatures it is extremely 
palatable and not at all injurious. 

Ice-cold beverages should be avoided, espe¬ 
cially during the hot days of summer, the season 
of the year when such drinks seem most agree¬ 
able. It is harmful to fill the stomach with 
ice-cold water when one is very warm. 

“Full many a man, both young and old, 

Has gone to his sarcophagus 
By pouring water icy cold 
Adown his hot esophagus. 


n8 


HEALTH READER 


What is meant by pure drinking water? By 

“pure drinking water” we do not mean a liquid 


that consists of nothing 
but absolutely pure 
water. Pure waters are 
extremely difficult to ob¬ 
tain. The purest are 
those produced by the 
condensation of steam 
from boiling water. But 
even such water may con¬ 
tain gases, which are car¬ 
ried with the steam. 
Moreover, the water may 
boil so violently as to 
send particles of other 
substances into the steam 
and so into the condensed 
water. Absolutely pure 



Diagram of a well 


water can be obtained only by the most carefully 
controlled chemical operations. Distilled water 
on sale in drug stores is reasonably pure. The 
rain water which comes after it has rained a 
long while is almost pure, but not entirely so. 

Pure drinking water really means water that 
is free from any dangerous infection and contains 
only a reasonable quantity of dissolved matters. 
The purest natural waters are those which come 
from deep springs or wells situated in localities 














FUNCTION OF WATER IN HEALTH 119 

where the rocks are highly insoluble and which 
are far removed from manufacturing industries 
and human habitations. 

The waters in springs 
found on uninhabited 
mountains may be re¬ 
garded as types of the 
purest drinking waters. 

Water coming from great 
depths, as in Artesian 
wells, is often reason¬ 
ably pure so far as free¬ 
dom from organic infec¬ 
tion is concerned, but it 
is often highly charged 
with dissolved mineral 
substances. 

Absolutely pure water, even if it could be 
obtained in sufficient quantities, would not be 
the best for drinking. The dissolved mineral 
substances which are contained in spring and 
well water are favorable to health. Especially 
is this true of the lime, magnesia, and iron which 
such waters usually contain. 

Are we well supplied with well or spring water? 
No, the greater number of people in the United 
States live in towns and cities. The water 
supply for the towns and cities is often taken 
from a near-by lake or river. Waters from such 




120 


HEALTH READER 


sources are nearly always impure or polluted. 
They carry, in addition to harmless mineral 
substances, large quantities of organic, matter 
derived largely from manufacturing industries 
and from human habitations. Many such 
waters are not pure and are extremely danger¬ 
ous for drinking. 

How are these waters made suitable for use? 

In some places the waters are used for drinking 
without any purifying treatment. In such 
localities typhoid fever and other disease germs 
are sometimes found in the water. 

The two principal methods of purifying the 
water of running streams and rivers to make it 
suitable for drinking are filtration and purifi¬ 
cation by chemicals. These two methods are 
often combined. The water is first treated with 
chemicals to start the purification, and is after¬ 
wards filtered. The filtering medium is usually 
sand. When infected or dirty water passes 
through the filter bed it deposits among the sand 
particles the silt , or fine mud, which it carries, 
so that the muddy or infected water comes out 
of the sand filter reasonably pure. 

Nearly all our large cities which get their 
water from running streams use some kind of a 
filtering apparatus. In many places the waters 
are first treated with chemicals to destroy the 
organisms that are injurious to health. Lime, 


FUNCTION OF WATER IN HEALTH 121 

chlorinated lime, sulphate of iron, and alum are 
the principal elements used for purifying water. 

How does such treatment of water safeguard 
health? Water purified for drinking purposes 
is practically free from disease-producing germs. 
Therefore such diseases as typhoid fever, chol¬ 
era, and dysentery, which may be transmitted 
through water, are prevented if the water is 
purified. Severe epidemics of typhoid fever 
have been caused by a polluted or impure 
water supply. 

Polluted water in streams and rivers also 
injures the fish, oysters, and crabs that live 
there. Shad at one time entered the Hudson 
River in as great numbers as they do the 
Potomac. But the sewage of New York has 
polluted the waters of the lower Hudson and 
now few shad pass through to the purer water 
above. When these unclean waters are carried 
to oyster beds, the oysters themselves may 
become infected. Numerous cases of typhoid 
fever have been traced to the eating of oysters 
that have been taken from waters made impure 
by city sewage. All this shows the immense 
importance of a pure water supply to a city. 
In all cases where perfect protection is secured 
the drinking water is boiled. 

How much water should we drink at our meals ? 
It has often been said by writers on health that 

5-T 


122 


HEALTH READER 


it is not desirable to drink while eating, because 
the use of a beverage while chewing tends to 
restrict the flow of saliva. Hence, since it is a 
necessity to mix enough saliva with the food to 
start the process of digestion, to drink a great 
deal while eating is injurious. * 

We should also learn to chew our food well. 
As a rule we swallow it too soon after we put 
it into our mouths, and the use of a beverage 
during mealtime encourages this habit. This is 
another reason why we should take very little 
liquid while we are eating. 

Recent investigations have shown that to 
drink moderate quantities of water with our 
food does not seem to prove injurious, and may 
even promote digestion. When studying the 
process of digestion we find that it depends 
upon the action on the food of certain ferments. 
If the mass of food is too dry these ferments 
have difficulty in reaching it. If there is too 
much liquid, they become less active. 

If a person eats a very starchy food he should 
not drink water while eating, but he may do so 
immediately afterwards if he feels the need of 
it. Starchy foods are digested largely by the 
saliva and hence should be chewed as long as 
possible, so that the salivary glands—the glands 
that produce the moisture of the mouth—may 
act as vigorously as possible. In eating meat, 


FUNCTION OF WATER IN HEALTH 123 


the saliva is not important, and liquids may 
be used with less harm than when one is eating 
foods such as potatoes and bread. 

In all cases, the drinking at meals of large 
quantities of liquids other than water, unless 
it be milk, is not advisable. It is better to 
wait until after the meal. Then we may drink 
water without injury to the digestive process. 

It is certain, however, that articles of food, 
except juicy vegetables, do not contain enough 
water for the needs of the human body, and it 
is therefore desirable to drink additional water. 
The amount required varies greatly with the 
tastes and habits of the individual and the 
character of his food. If we eat juicy foods, 
such as turnips, lettuce, celery, asparagus, 
green peas, green beans, or green corn, we need 
very little additional water. If, on the other 
hand, we eat bread, meat, sugars, and oils, we 
need a great deal more water. 

An abundance of water at the right time 
has a favorable effect on the digestion. It 
keeps the contents of the intestines from becom¬ 
ing too hard, and thus aids in preventing con¬ 
stipation. A good practice is to drink a tumbler 
full of good water at a temperature of sixty 
to sixty-five degrees immediately on rising each 
morning and to take the same amount before 
going to bed at night. 


124 


HEALTH READER 


In general, the degree of thirst determines 
the quantity of water that should be drunk. 
You are not likely to injure your health by 
drinking too much water, if it is pure and of 
the proper temperature. 

What happens if you drink more than thirst 
requires? Usually a little more water than is 
normally required to satisfy thirst will not 
prove harmful. The healthy body keeps the 
proper balance of water in the blood. If a 
little too much water is taken, it is eliminated 
without much trouble through the kidneys, 
through the skin, and in other ways. But in 
diseased conditions of the body, as in a harden¬ 
ing of the arteries or in diseases of the heart, 
an excess of water may prove harmful. The 
excretory organs are then unable to do their 
full duty, thus increasing the volume of the 
blood and throwing an additional burden on 
the heart and the imperfect arteries. These 
diseases do not usually attack children or young 
people, but are common in later life. People 
past forty or fifty years of age, whose blood 
pressure is above the normal, should limit the 
quantity of liquids in their foods to the smallest 
amount necessary for proper digestion. This 
is a matter to be decided by the physician and 
not by the schoolbook. 

Is water used as a medicine? The use of water 


FUNCTION OF WATER IN HEALTH 125 

in keeping clean is to a certain extent medi¬ 
cinal. Washing the hands is distinctly an 
attack upon disease, for clean hands are less 
liable than dirty hands to carry disease to the 
mouth or to impart disease to others. The 
common habit of washing the hands and face 
in the morning is to be commended from a 
point of view both of cleanliness and of health. 
It is well to repeat this operation at noonday 
and at night. 

The bathing of the whole body is likewise 
a health measure. Water and a little soap, the 
rubbing which one receives in bathing, and the 
drying with a coarse towel, tend to promote 
the healthy action of the skin. These things 
all help to supply the body with the proper 
amount of blood, and to keep the pores open 
and in condition to perform their normal 
functions. For the same reason massage—the 
kneading and pounding of the body—is also 
conducive to good health. The use of water, 
therefore, is one of the most valuable methods 
of preventing disease, for through water we 
secure cleanliness. 

Is water ever used in sickness? Water is 
constantly used as a remedy by physicians. 
Because of its great power of absorbing heat 
it is used very generally in cases of fever, either 
in the liquid state or frozen. Bathing the body 


126 


HEALTH READER 


of a person suffering from fever cools the surface 
of the body and is refreshing to the patient. 
Copious drafts of water, usually warm water, 
are used internally to produce vomiting. If a 
little salt is added to the water, it acts'more 
promptly. For this purpose the water should 
be lukewarm, neither very hot nor very cold. 

What is meant by “taking the waters”? Those 
persons who go to drink the waters from mineral 
springs which are reputed to be of value in 
certain diseases are said to be “taking the 
waters.” When people go to the springs they 
are placed on a rigid diet, usually very simple, 
consisting of a little fruit and hard bread, the 
water of the spring being their only beverage. 
The waters at such springs are usually known as 
mineral waters; that is, they contain more of 
the materials derived from rocks than ordinary 
spring or well water. These materials or mineral 
substances have a medicinal action. The water 
contains more or less lime, an excellent remedy 
for many diseases. The benefit which people 
secure at the springs is probably due as much 
to the rigid diet on which they are required to 
live as it is to the use of the mineral waters 
themselves. 

Could life be continued without water? Water 
„ is as necessary to a living being as air or food. 
If you were deprived of water you would die as 


FUNCTION OF WATER IN HEALTH 


127 


quickly as if you were deprived of food, or even 
more quickly. 

If you have plenty of food, even though it is 
dry, a good deal of water will be generated 
when the food is eaten, because all the hydro¬ 
gen which the food contains will be burned into 
water in the body. But even that quantity of 
water is insufficient to support life for more 
than a short time. The average amount of 
water in the ordinary foods we eat is about 
seventy-five per cent, but even with so much 
water we are required constantly to take ad¬ 
ditional quantities. You can readily imagine 
what would happen if all our foods were entirely 
dry and we had no access to water. We should 
live only a few days. 

Long ago the Latins had a motto which, when 
translated, reads: “Bodies do not act unless 
they are in solution.” Water, as has already 
been said, is the universal solvent. All the 
foods we eat must pass into solution in water 
before they can be taken up into the blood. 

QUESTIONS TO HELP THE PUPIL 

1. Can we see carbon dioxide and water when they are 
in the form of gas? 2. What substance do we see in the 
smoke that goes up the chimney ?. 3. What happens to 
the water in the breath when the air is cold? 4. Of what 
substances is water composed? 5. What happens when 
you put sugar in water? 6. Does hot water dissolve 
substances more rapidly than cold water? 7. What 


128 


HEALTH READER 


substance is an exception to this rule ? 8. What is a mineral 
water? 9. Why is water called the “universal solvent”? 
10. Tell what happens when water is heated. 11. What 
proportion of the human body is water? 12. What pro¬ 
portion of water do most foods contain ? 13. Name some 

foods that contain less than this proportion. Some that 
contain more. 14. Why are we thirsty in hot weather? 
15. Why do persons who drink alcoholic beverages become 
thirsty ? 16. What are three natural reasons for becoming 

thirsty? 17. What are soft drinks? 18. What injurious 
substances do some soft drinks contain? 19. What is 
best for us to drink? 20. Should we drink very cold 
water? 21. What is the best temperature for our drink¬ 
ing water ? 22. What is * ‘ pure drinking water ” ? 23. Are 
the dissolved mineral substances found in spring water 
good for us? 24. What is the best location for a well? 
25. From what sources do most cities and towns get their 
drinking water? What is the danger? 26. How may 
water be purified for use as drinking water? 27. What 
diseases may be transmitted through polluted water? 

28. How may polluted water cause sickness indirectly? 

29. Should we drink much while eating? 30. What bad 
habit in eating is encouraged by drinking while eating? 
31. Is it best to drink after a meal? 32. What foods 
require saliva for their proper digestion? 33. What is a 
good practice in drinking? 34. Why is too much water 
injurious? 35. How may the use of water prevent 
sickness? 36. To what uses is water put in sickness? 
37. What is meant by “taking the waters”? 38. What 
minerals do spring waters chiefly contain? 39. Is the 
rigid simple diet of as much benefit as the waters them¬ 
selves? 40. Could we live without water? 41. Through 
what process must all foods pass before they can be 
taken up into the blood? 


PART TWO 

XIII. Food and Why We Need It 

What is food? That is a very important 
question. Food is necessary to life. Without 
it we should soon die of starvation. The work 
of men is largely done in order to obtain food. 
Food is necessary also to health and growth. 
Without proper food the child cannot grow as 
he should. No one, young or old, can be 
healthy without suitable food. Every one who 
studies, plays, or works must be properly nour¬ 
ished. In all our plans for life and happiness, 
food must be considered. 

Every person is at his best only when supplied 
with good food. The family cannot do its 
work at home or in society unless it is supplied 
with good food. The community cannot be¬ 
come prosperous and progressive without good 
food. The state would fail in its efforts to 
establish good government and protect the 
^rights of its inhabitants without an abundant 
food supply. The nation engaged in war cannot 
continue fighting for any length of time without 
a large food supply. The most progressive 
races of men are those that have good food 
in plenty. Thus, from every point of view, we 


129 


130 


HEALTH READER 


find that food, above all things except air and 
water, is necessary to life, to effective work, and 
to happiness. 

For this reason the answer to the question, 
What is food? is of great importance: Food is 
that which , taken into the body , promotes growth , 
restores waste tissue , and provides heat and energy . 

QUESTIONS TO HELP THE PUPIL 

i. Why is food so important? 2. Is good food neces¬ 
sary to health? 3. What would happen if we did not get 
enough food? 4. Is effective work or happiness possible 
without plenty of good food? 5. What other things be¬ 
sides food are absolutely necessary to life? 6. What is 
the function of food in the body? 


XIV. The Articles of Food 

What are the articles which serve as food? We 

all know from everyday experience what is 
generally regarded as food. When we speak 
of food we think of milk, bread, meat, fruit, 
and vegetables, for the food we eat consists 
largely of these articles. There are still other 
articles which serve as foods though they are 
not usually thought of as such. In the first 
place, water forms an important part of the 
foods we consume. And, in that sense, water is a 
food, though we usually speak of it as a beverage. 
Again, the oxygen of the air plays an active 



part in nourishing the body, and especially in 
providing heat and energy. To that extent 


























132 


HEALTH READER 


the oxygen which enters the lungs is really a 
food, though it is not included under what 
we commonly term food. 

There is another class of articles, called con¬ 
diments , used chiefly to give relish or seasoning 
to food. Some condiments are foods and others 
are not. Common salt, for instance, is a condi¬ 
ment; but it is also a food, since it is necessary 
to the proper nourishment of the body. 

Are useful substances ever harmful? When used 
in too large quantities common salt, instead of 
being useful, becomes harmful. This is true of 
every good substance. You can drink so much 
water that your blood becomes diluted. This 
increases the bulk of the blood, and so places a 
heavier burden on the heart, the arteries, and 
the veins, and also on the kidneys and other 
excretory organs , which separate or discharge 
waste and harmful material from the blood or 
tissue. In this way water becomes harmful. 
You can eat enough bread to overload your 
stomach and so cause indigestion. You can 
drink so much milk that you will be made ill. 
And so with every good thing. Its right use is 
beneficial; its wrong use is harmful. 

Why should we avoid useless substances? 
There is a great difference between articles 
which are useful and good when not used to 
excess, and those which in themselves are useless 


THE ARTICLES OF FOOD 


i 33 


and also harmful. Because common salt is 
harmful when too much is used is no excuse for 
using benzoate of soda , a common food preserv¬ 
ative, which never does any one any good no 
matter what the quantity used. A useless sub¬ 
stance in the body, no matter how small the 
quantity, must be harmful since the energy of 
the body must be used in some way to get rid 
of it. In the long run any useless expenditure 
of energy is harmful. 

Are we in danger of eating too much salt? Salt 
is often used in foods which would be better 



Deer at a salt lick 


without it. An instance of this is its use in 
butter. In this country we are accustomed 




134 


HEALTH READER 


to salted butter; in other countries it is served 
unsalted. If we used unsalted butter we might 
soon learn to like it better than when salted. 

We are also inclined to use too much salt 
on our meats. The proper place to use salt 
is with our vegetable foods. Animals that live 
on vegetables require more salt to enable the 
organs of the body to perform their proper 
functions than those that live on meats. Wild 
plant - eating animals, 
such as the buffalo and 
the deer, will travel 
many miles in order 
to reach a salt lick, a 
place where salt is 
found on the surface. 
Those of you who live 
on farms are familiar 
with the general cus¬ 
tom of giving salt to 
sheep, horses, and cattle. On the other hand, 
flesh-eating animals, such as dogs and cats, do 
not require much salt. This is because there is 
naturally much salt in all flesh and very little 
in vegetables, and because plants contain much 
potash which common salt helps to eliminate. 

The desire for an excessive amount of salt 
in our food is largely a matter of habit which 
can easily be overcome. 



















THE ARTICLES OF FOOD 


i 3 S 

Are there other condiments in foods? There are 
many condiments besides salt used in foods. 
Some of these, such as mustard and some forms 
of pepper, have a certain amount of food value. 
Others, such as vanilla and other flavoring 
extracts, have little or no food value. The 
principal condiments are salt, pepper, mustard, 
cinnamon, ginger, and the flavoring extracts. 

A particular flavoring substance is developed 
by burning wood. This substance, which is 
present in the smoke from the burning wood, 
is regarded as a condiment and is usually classed 
as such. Ham and bacon owe their flavor in 
part to this condiment. 

Not salt alone, but all condiments, may 
become injurious if used to excess. But when 
properly used they are beneficial, for condiments 
induce an increased flow of the liquids that aid 
digestion. 

QUESTIONS TO HELP THE PUPIL 

1. What are the common articles of food? 2. Is water 
a food? 3. Is oxygen called a food? 4. Name another 
class of foods. 5. When do useful substances become 
harmful ? 6. Why is benzoate of soda harmful? 7. What 

can you say about the quantity of salt generally used? 

8. With what kind of food is it most proper to use it? 

9. What animals need salt? Why? 10. Name some 
animals that do not require much. Why?- 11. Name 
some condiments besides salt. 12. What must we avoid 
in the use of condiments? 13. Why are condiments 
beneficial when properly used? 


XV. The Flavor of Foods 

What is flavor in food? Flavor in food is a 
combination of taste and odor. We get it 
through the combined action of the tongue and 
the nostrils. It is not correct to say that we 
get the flavor of food through the mouth alone 
or through the nose alone. What we get in the 
mouth is the taste, and what we get through 
the nostrils is the odor; the combination of the 
two is flavor. For instance, sugar alone has a 
taste but no odor, while vanilla is especially 
valued for its odor. But by combining sugar 
and vanilla we get a pleasing and distinct flavor. 
We all know this fine flavor in cake we have eaten. 

Flavor is an important element in the proper 
digestion of food. If we were to take our food 
through a tube inserted into the stomach, 
which is entirely possible, we should get from 
it neither a sense of smell nor a sense of taste. 
At the same time our digestion would be greatly 
impaired and the food would not properly 
nourish the body. Thus the forcible feeding of 
prisoners who try to commit suicide by starving 
themselves may save their lives, but it does 
not give them the full benefit of the food. 

Condiments all affect either the sense of 
taste or the sense of smell, and usually both. 

136 


THE FLAVOR OF FOODS 


i 37 


Condiments, therefore, are important aids to 
digestion, because they produce or heighten 
food flavors. 

Do foods themselves have flavors? Yes, most 
food products have flavors. Those that have 
well-marked flavors do not need the addition 
of a condiment. Good types of such foods 
are the apple and the orange. These products 
have not only an agreeable odor but also a 
pleasant, sweet-acid taste. This combination 
of odor and taste produces a fine flavor. 

No one should think it necessary to add any 
condiment to such fruits in order to produce 
flavor. The addition of pure sugar is not the 
addition of a flavor, because refined sugar, hav¬ 
ing no odor, does not fall within the definition 
of a flavor. When cooked, acid fruits are often 
sweetened with sugar, and sometimes condi¬ 
ments, like cinnamon or nutmeg, are added for 
flavoring purposes. But in the raw state, and 
it is thus that the fruits have their best flavors, 
such additions would be out of place. Prac¬ 
tically none of the common foods we eat in the 
raw state needs condiments. Melons, berries, 
and nuts all have distinctive flavors and are 
for the most part eaten without condiments. 
Some nuts are improved to the taste of many 
persons by the addition of salt, but few are 
really made better thereby. 


138 


HEALTH READER 


Does cooking develop flavor ? Cooking or 
roasting develops flavor in a great many sub¬ 
stances without the addition of condiments, 
though it is to the cooked foods, most of all, 
that condiments are added. Some common 
examples of flavor developed by roasting are 
found in the coffee bean and in peanuts. The 
peanut, though edible in the raw state, is far 
more agreeable to eat when it is roasted. The 
roasting develops taste and odor—that is, flavor. 
The coffee bean has a better and an entirely new 
flavor after being roasted. In fact, a drink 
made from the raw coffee bean would not appeal 
to the taste. The flavor of meats is always 

brought out 
to a great de¬ 
gree by roast¬ 
ing. This is 
true also of 
bread when it 
is baked. 

Condiments 
affect the 
nerves of 
taste, which 
are in the 

A street peanut roaster . 

tongue, and 

also the nerves of smell, which are in the 
nostrils. These nerves are connected directly 











THE FLAVOR OF FOODS 


i39 

and indirectly with the digestive organs. A 
good taste and a good odor in food aid in 
exciting the ac¬ 
tivity of the di¬ 
gestive organs. 

When you are 
very hungry, 
and you get the 
odor of the 
dinner being 
cooked, your 
mouth waters. 

That is, the 
nerve of smell 
— the olfactory 
nerve has car mouth, showing salivary glands 

I*ied a message a, parotid glands; b, submaxillary glands; c, sub¬ 
lingual glands; d, salivary ducts; e, tongue 

to the salivary 

glands that something good is coming, and 
these glands, which discharge saliva into the 
mouth, get ready to welcome the visitor. In 
other words, your “mouth waters.” Then 
when you place on the tongue a bit of food 
that tastes good, the nerve of taste sends a 
message to the glands in the stomach that 
secrete the pepsin , and those glands get ready 
to aid in digesting the food. If you put butter 
on your bread and get both the taste and the 
odor of butter, these nerves send a message 





140 


HEALTH READER 


to the large gland called the pancreas , which 
discharges into the intestines, and the pan¬ 
creas prepares to welcome the visitor by 
secreting the fluid which will digest the fat. 
Thus, through odor and taste, all the organs 
which are active in the digestion of food receive 
advance notice of the approach of the food 
and make preparations to do their part in its 
digestion. 

Is there danger in using condiments too freely? 

The answer to this question is the same as that 
in regard to salt. In order to avoid excess, 
condiments should be used sparingly, with 
judgment, and with great care. The skilled 
French cook, instead of putting onion directly 
into his sauce, will simply rub the spoon with 
which the sauce is served 
with an onion. He thus 
gets a fine, delicate flavor, 
instead of the full strength 
of the onion. The proper 
use of condiments is a mark 
of the skilled and expe¬ 
rienced cook. Those not 
skilled in the use of condi¬ 
ments should make up for 

The onion plant thek lack Q f know l e dge by 

using them in very small amounts. 

The ability to use the heat of the oven in 




THE FLAVOR OF FOODS 


141 

developing taste, odor, and flavor is also a 
marked characteristic of the good cook. 

Are condiments re¬ 
garded as food prod¬ 
ucts? Condiments 
are not commonly 
regarded as food 
products. But in the 
law of our country 
everything we con¬ 
sume for our nourish¬ 
ment or pleasure is 
regarded as food. 

According to the 
Food and Drugs Act 
of the United States food includes not only 
those things which are commonly considered as 
food, but also beverages, condiments, and con¬ 
fections. This law is usually called the “pure 
food law ’ ’ because it requires that all articles of 
food made or put up for sale be clean and pure. 

QUESTIONS TO HELP THE PUPIL 

1. What is the flavor of a food? 2. Does flavor aid 
digestion? 3. How do condiments aid digestion, if used 
properly? 4. Should condiments be added to raw fruits? 
5. What food substances have their flavor developed by 
roasting? 6. In what quantities should condiments be 
used? 7. What is the “pure food law”? 

8. What nerves do condiments affect? 9. With what 
are these nerves connected? 10. What happens when 
you smell a good dinner or taste a good food? 



XVI. Differences in Foods 

How do foods differ? No two foods are ex¬ 
actly alike. Even if of the same variety there 
may be great differences between them. All 
the foods we eat, even those of the same kind, 
vary according to the locality 
in which they are grown, 
the conditions of climate or 
season, and the methods used 
in harvesting and handling 
them. A pippin (one kind of 
apple) grown in Virginia may 
An apple be q U ite unlike a pippin grown 
in California, though both apples grew on the 
same kind of a tree. The environment in which 
food grows — in other words, air, sunshine, rain, 
and soil — has a great deal to do with its char¬ 
acter as well as the kind of food it represents. 

Foods differ in many other respects. It is 
very important that we understand in a prac¬ 
tical and simple way just what some of these 
differences are. 

What are the most common articles of food ? In 

general, when we sit down at a table we expect 
to have bread. A meal without bread, though 
such meals are sometimes served, never seems 
quite complete. Especially is this true of 



142 


DIFFERENCES IN FOODS 


i 43 


the home table. Bread may be considered a 
universal food among all nations where the art 
of bread making is known. Under the term 
“bread” we include the many varieties of foods 
made from such cereals as wheat, Indian corn, 
oats, and rye. 

Another article we usually expect to have at 
a meal, especially at dinner, though it is not 
so universally eaten, is meat. Under the term 
“meat” we may include as many different kinds 
of products as we do under the term “bread.” 

A third article we are usually given at a meal 
is a vegetable of some kind. In common lan¬ 
guage the term “vegetable” is not applied to all 
plant-food products. Potatoes, green peas and 
beans, radishes, and 
beets are thought of 
as types of the class 
of foods we commonly 
call vegetables. 

Our ideas of a meal, 
in other words, lead us 
to think at once of 
three great classes of 
food: bread, meat , and 
vegetables. It would 
not be fair to leave 
out fruit, although fruit is not nearly so com¬ 
monly served at meals as vegetables. It 





Oranges 



144 


HEALTH READER 


would be well if it were used more. A true 
saying is, “An apple a day keeps the doctor 
away.” It is unfortunate that so large a 
number of our people do not have the privi¬ 
lege of eating fruit every day. It would be 
wise for the one who provides for the table to 
serve less meat and more fruit and vegetables. 

May foods be classified in other ways than as 
bread, meat, vegetables, and fruit? These terms, 
bread, meat, vegetables, and fruit, are used to 
denote the articles usually thought of as foods. 
But regarded from the scientific point of view, 
the term “food” applies to the elements of 
nourishment which these articles contain rather 
than to the articles themselves. 

We have in our bodies certain tissues — 
namely, bones, muscles, tendons, nerves, brain, 
skin, and hair. These tissues have different 
characteristics; that is, they are made up of 
varying amounts of different kinds of elements 
and require different kinds of nourishment. 
The scientific view of nutrition is to feed these 
tissues the elements of nourishment they need, 
selecting from among the different articles 
of food those which most nearly supply their 
wants. 

There are four principal foods, or elements 
of nourishment, necessary to the sustenance of 
the body. First, starches and sugars, together 


DIFFERENCES IN FOODS 


i45 


known as carbohydrates , a word which means 
“water united with carbon.” 

Sugars are much more soluble , or easily dis¬ 
solved, than starches. They are extremely 
soluble in water, while starches are scarcely at 
all soluble in cold water and only to a limited 
degree in hot water. If you boil a little starch 
with water it seems to dissolve, but as a matter 
of fact the starch is only suspended in the water 
in the form of a paste. If you put sugar in water 
the sugar rapidly disappears, and exists through¬ 
out the water in a state of complete solution. 

As foods, sugars and starches are much 
alike; they serve the same purpose in the body, 
and together they constitute by far the largest 
part of our food. 

What are the principal starch foods used? The 

cereals—wheat, corn, barley, rye, rice, oats, 
buckwheat — form with potatoes the principal 
food supply of man. They are also the most 
important starch foods he uses. In some coun¬ 
tries, as in rice-eating China and Japan, cereals 
provide almost all the food supply. In other 
countries the principal article of food is made 
from rye, as in Russia and in parts of Germany. 
In still other countries, like France, England, 
Scotland, the United States, and Canada, the 
principal cereal products used for food are 
wheat and oats. 


146 


HEALTH READER 


Cereals in general, when ground into flour or 
meal, contain seventy per cent of starch and 
twelve per cent of water, 



although certain cereals 
vary somewhat from 
these figures. Thus it is 
evident that when cereals 
are eaten the great bulk 
of the food is composed 
of starch. 


Among other starch 
foods the potato con¬ 
tains about twenty-two 
per cent of solid food 
and seventy-eight per 
cent of water. Of the 
twenty-two per cent of 
solid food more than 


The sago palm 


three fourths is starch. Peas and beans also con¬ 
tain considerable quantities of starch, though in 
these articles the starch is not the principal 
ingredient. There are certain other foods — 
such as the cassava , which grows in Florida and 
the tropics; the taro , a starchy food which grows 
abundantly in the Hawaiian Islands; and sago — 
the food elements of which consist largely of 
starch. 

Thus we learn that the principal starch foods 
are cereals, potatoes, sago, cassava, and taro. 







DIFFERENCES IN FOODS 


i 47 


From what products do we get the principal sugar 
foods? Practically all the foods we eat contain 
sugar. Some 
of them, such 
as the cereals, 
contain an ex¬ 
ceedingly small 
quantity of 
sugar, not over 
one or two per 
cent. Others, 
like the refined 
sugars we buy, 

Consist almost Cassava roots, from which tapioca is made 

entirely of sugar, the percentage being about 
99.95. We eat sugar in two forms, first as an ele¬ 
ment of our common foods. In this we have no 
choice; we must eat the sugar if we wish to eat 
the foods. Second, we eat sugar that has been 
extracted from plants and prepared for our use 
in the form of molasses, sirups, raw sugar, and 
refined sugar. We eat these simply as sugars, 
or after they have been added to pastry, con¬ 
fections, and candies. 

Among the foods that are rich in sugar, milk 
may be mentioned first. Milk contains from five 
to eight per cent of sugar, according to the kind 
of milk. Ordinary cow’s milk contains about 
five per cent of sugar. Beets, especially sugar 



148 


HEALTH READER 


beets, contain a large amount of sugar, some¬ 
times as much as fifteen to eighteen per cent. 

Turnips, radishes, and car¬ 
rots contain from two to five 
percent. Fruits of all kinds 
contain a large amount of 
sugar, from seven to fifteen 
per cent, and some kinds of 
grapes contain even more. 

Thus, whether we eat 
cereals, drink milk, or eat 
vegetables or fruit, we are 
continually taking into our 
stomachs large quantities of 
sugar. When we eat cakes, 
pastry, confections, and 
candy we take still greater quantities. Some 
of these latter foods are composed almost 
entirely of sugar. So far as digestion and 
nutrition are concerned, sugar and starch have 
the same properties and may be considered as 
one and the same substance. 

What relation has sugar to health? A large 
amount of sugar in the food tends to make one 
fat. Sugars and starches are regarded as even 
more likely to cause obesity or stoutness than 
fat or oil. People who are inclined to become 
fat should eat as little sugar as possible. They 
should not put it on the cereal at breakfast 



A sugar beet 


DIFFERENCES IN FOODS 


149 


nor use it with strawberries and cream at lunch, 
and they should avoid ice cream at dinner. An 
excess of sugar in the body is dangerous. The 
alarming increase in this country of the disease 
called diabetes may possibly be due in a degree 
to the large increase in the consumption of 
sugar. For the same reason candy eating 
among children is extremely injurious to their 
health. Sugar may make children fat, but it 
does not make them healthy. They get all the 
sugar they need in their usual food. Too much 
sugar and candy also prevent the development 
of good teeth. Children should not eat candy. 

After starch and sugar, what is the next important 
food element ? Judged by the quantity in which 
it occurs in food products, the most important 
food element after the carbohydrates, starch 
and sugar, is what is known as protein . Protein 
is the name given to that class of foods, so 
important in human nutrition, which contains 
as two of its distinctive elements nitrogen , 
meaning “ niter producer,” and sulphur . Many 
of the proteins contain other important nourish¬ 
ing elements also, as for instance phosphoric acid , 
used in forming bones and teeth. A pure pro¬ 
tein, however, may not contain any phosphoric 
acid, but may consist entirely of nitrogen, sul¬ 
phur, hydrogen (water former), carbon (coal), 
and oxygen (acid former). Usually a pure 


HEALTH READER 


150 

protein, such as dried white of egg, which is 
about the purest form known in nature, contains 
about sixteen per cent of nitrogen and one per 
cent of sulphur. The other eighty-three per cent 
are composed of hydrogen, oxygen, and carbon. 
The principal sources of the protein in our 
foods are the cereals, and after them especially 
the lean meat, red or white, of all edible animals, 
and lastly eggs, peas, and beans. 

What is the third important food element? 
Judged by quantity alone, the third important 
food element is fat or oil. The butter and lard, 
olive oil, cotton-seed oil, and other edible oils 
which we consume with our foods consist very 
largely of fat and oil. Of the different parts 
of the hog, the bacon is almost all fat, while 
the ham is mostly protein. Butter is an im¬ 
portant fat food, more than eighty per cent of 
it being pure fat. Many nuts also are com¬ 
posed largely of oil; for instance, the peanut is 
about forty per cent oil. The same is true of 
the almond and the walnut. On the other 
hand, the chestnut contains a large amount of 
starch as well as a considerable quantity of oil. 
So in eating nuts one gets, as a rule, a large 
quantity of oil. 

What is the next most important class of food 
elements? Again judged by quantity alone, the 
fourth and last class of food elements consists 


DIFFERENCES IN FOODS 151 

of what we call ‘‘mineral substances.” When 
a food substance is burned, the ash that is left 
represents the mineral matter that the food 
contains. The quantity of ash present in 
food products varies greatly. Some foods con¬ 
tain as high as three or four per cent of ash, 
while others contain less than one per cent. 
This mineral matter consists of various sub¬ 
stances, certain of them being important to 
nutrition. Among these are phosphorus and 
lime, which are used in the body to form a 
considerable part of the bones and the teeth. 
The other minerals play parts of greater or less 
importance. Thus we see that the mineral 
elements of food, although least in quantity, are 
quite as necessary for proper nutrition as the 
larger quantities of fat, protein, and starch 
which our food contains. 

In a -general way it may be said that for 
every one hundred pounds of food we eat, two 
pounds should be mineral substances. Among 
these phosphorus, sulphur, chlorine, lime, iron, 
magnesia, salt, soda, and potash are the most 
necessary. 

Is there another food element besides the 
four classes described? An important element 
besides those we have been studying has recently 
been discovered in certain food products. This 
element has been given the name vitamines . 


152 


HEALTH READER 


It is still uncertain of just what ingredients 
this element is composed, but it is known that 
vitamines are substances that are very active 
in aiding the process of digestion. They also 
greatly increase the nourishing value of other 
food elements with which they are found. Vita- 
mines are thought to contain phosphorus and 
perhaps nitrogen and hydrogen, and are found 
principally in the bran of cereals, in milk, fruit, 
and vegetables. These foods, we have learned, 
already contain very valuable food elements, 
the vitamines increasing their nourishing value 
still more. It has been discovered that these 
foods should be eaten in a natural state, that 
is, with as little cooking or refining as possible, 
in order to get the most benefit from the vita¬ 
mines they contain. 

Are the acids which exist in foods of value in 
nutrition? The acids found in certain food 
products play an important part in nutrition. 
They are to be classed with the condiments, and 
thus become food products. The acids found 
in certain kinds of fruit are also very generally 
found in all vegetable substances, though only 
in small quantities. 

In the sap of such sugar-producing plants as 
sugar cane, sugar beets, and sorghum, and in the 
sap of the maple tree, there are large quanti¬ 
ties of acids. Most of these acids are the same 


DIFFERENCES IN FOODS 


iS3 

as the acid contained in apples, an acid which 
is called malic acid. Other vegetable acids 
are frequently found in 
sugar-producing plants 
of this kind but in small 
quantities only. Citric 
acid is found in lemons 
and oranges, and tar¬ 
taric acid in grapes. 

All these acids are com¬ 
bined in the fruit with 
other substances, prin¬ 
cipally potash. 

Because these acids 
improve the taste of 
the foods in which 
they are found, they 
are condiments. When digested they produce a 
certain amount of heat, and so have a food value 
as well as a condiment value. They also perform 
a useful service in carrying into the body the 
soda and potash with which they are combined. 
These acids are wholesome when eaten in the 
foods in the combination in which they natu¬ 
rally exist, but they would not be wholesome if 
extracted from the foods and used as pure acids. 

QUESTIONS TO HELP THE PUPIL 

i. What causes differences in the same kind of food 
grown in different localities? 2. What are the three most 



Cutting sugar cane 


6 



154 


HEALTH READER 


common articles of food? 3. What is a universal food? 
4. What is a fourth article of food that should be used 
more than it is? 5. What is the saying about an apple? 
6. To what does the term food apply scientifically? 7. 
What is one of the four principal foods necessary to nutri¬ 
tion? 8. Which is more easily dissolved, sugar or starch? 
9. Name the principal starch foods. 10. Are sugars and 
starches much alike? n. By what common name are 
wheat, corn, barley, rye, rice, oats, and buckwheat known? 

12. What general percentage of starch do cereals contain? 

13. How much of the solid food in the potato is starch? 

14. What other starch foods have you eaten? 15. In what 

forms do we eat sugar? 16. What food do you know that 
is rich in sugar? 17. What vegetable is particularly rich 
in sugar? 18. What is the result of eating much sugar? 
19. What is obesity? 20. What sickness is indicated by 
the secretion of sugar from the body ? 21. What is another 

important food element besides the carbohydrates ? 
22. Of what substances is protein made up? 23. What 
is the purest form of protein in nature? What foods are 
the principal sources of it? 24. What is the third food 
element? 25. Name some important fat foods. 26. 
What is the principal element in nuts? 27. What is the 
fourth important class of food elements? 28. Name 
some important mineral substances. 29. What should 
be the proportion of mineral substances in our food? 
30. What important element has recently been discovered 
in foods? 31. What is the value of vitamines in 
digestion? 32. In what foods are vitamines principally 
found? 33. Of what value are the acids contained in 
foods? 34. With what class of food elements are acids to 
be classed? 35. Name the three classes of acids and 
several fruits containing them. 36. What is the value of 
these acids in nutrition? 

37. Do the different tissues in our bodies require differ¬ 
ent kinds of nourishment? 38. What is scientific nutri¬ 
tion? 39. Are starch and sugar alike so far as digestion 
and nutrition are concerned? 


XVII. A Study of the Articles of Food 

How may we know where to find and how to use 
the four principal elements of nutrition? The 

answer to this question is of great practical value. 
If we wish to keep well and be as useful as pos¬ 
sible we must not only know something of the 
nature of foods but, in order to secure the best 
results, we must know how to use them in a prac¬ 
tical way. It would not be practicable for us to 
weigh and analyze each portion of food set before 
us. Fortunately, we do not need to do this, for 
nature varies little in her work. In the amount 
of food elements they contain she makes foods 
of the same kind practically alike from year to 
year. So we need only know the average compo¬ 
sition of any staple food product to determine 
the correct proportion of that product that 
should be eaten. 

In order to be able to do this effectually we 
shall study some of the more important food 
products that are daily set before us. Every 
product contains, each in its own proportions, 
the elements of nutrition which we have noted. 

What is the average composition of milk? In 
our country the term “milk,” when used with¬ 
out qualification, means milk of the cow. Cow's 


155 


HEALTH READER 


156 

milk has been analyzed thousands of times in 
this and other countries, so that we know with 
practical exactness its average composition. 
This is set down in the following table: 


THE COMPOSITION OF COW’S MILK 


WATER 

MILK SUGAR 

(lactose) 

PROTEIN 

(casein) 

FAT 

(butter) 

MINERAL 

MATTERS 

87 per cent 

5 per cent 

3.4 per cent 

3.9 per cent 

.7 per cent 


One hundred pounds of milk furnish thirteen 
pounds of food in a dry state. These thirteen 
pounds of food contain the various food elements 
in the right proportions to furnish an ideal 
ration for the growing child, and especially for 


• Mineral Matter 

the infant. 

m, Protein 

Attention is 

mm Fo.t 

called to this 

mm Milk sugar 

water fact for the 

! ; ; ; ; | reason that in 

1 1 T * I 1 1 l 1 1 1 1 1 1 I I 1 1 ■ .. 

' -L ' iTC mmnncitmn 


100 its composition 


Composition of cow's milk milk is a model 

for selecting the food of the child after he is 
weaned and he ceases to be nourished wholly 
by milk. If this be a true guide, and there 
seems to be no doubt of the fact, then 
in choosing food for the growing child we 
should see that it contains all the elements of 
growth in about the same proportion as they 
exist in the dry matter of milk. Then from 
the above table we may obtain the following 













A STUDY OF THE ARTICLES OF FOOD 157 


table of proportions of the food elements in 
milk, excluding the percentage of water. 

IDEAL COMPOSITION OF FOOD FOR THE GROWING CHILD 


IN PARTS OF IOO OF DRY MATTER 


SUGAR AND STARCH 

PROTEIN 

FAT 

MINERAL MATTER 

38.46 per cent 

26.16 per cent 

30 per cent 

5.38 per cent 


There are traces of various other substances 
in cow’s milk, but these are so small in quantity 
that they need not be considered here. In 
order to simplify the above table, and make it 
more easily remembered, we may say that when 

making up a 
diet for chil¬ 
dren that part 
of it other than 
milk should be 
the follow- 


Mineral Matter 1 
Protein 
-4 Fo t 

—— Sugar and stareR 
TT 


I I" I I | 


r 1 "i 


| r 1 “i 1 


7S 


Ideal composition of food for the growing 
child 


m 
ing 
five 


propor- 
times the 


tions: The protein should be 
quantity of mineral matter; the fat six times the 
quantity of mineral matter; and the sugar and 
starch eight times the quantity of mineral 
matter. Representing the mineral matter by 
1, we have the following series of numbers: 1, 
5, 6, 8. These figures are easily memorized 


MINERAL MATTER 

PROTEIN 

FAT 

SUGAR AND STARCH 

I 

5 

6 

8 





















158 HEALTH READER 

They represent the food elements in the relative 
proportions in which they should be present in 
the food of the growing child. 

Is there any food product which can take the place 
of milk for the growing child? Yes, there is a 
common food product which is almost as well 

adapted for the 
growing child 
as milk. This 
food we call 
cereal, and it 
is advisable to 
use it in con¬ 
nection with 
milk for chil¬ 
dren beyond 
the age of in¬ 
fancy. The 
typical cereals 
are wheat, Indian corn (maize), rye, barley, 
rice, oats, and buckwheat. But children espe¬ 
cially should use a great deal of milk with 
cereals. Wheat is the best cereal, although 
it produces too much acid when eaten alone; 
milk corrects that fault. 

What is the average composition of wheat? Wheat 
is rightly regarded as the most valuable of the 
cereals used for bread making, and its com¬ 
position should be known to every one. 



Milking the cow 




A STUDY OF THE ARTICLES OF FOOD 159 

AVERAGE COMPOSITION OF WHEAT 


Weight of 100 grains of wheat 


GRAMS 1 

3-8 


Moisture. 

Protein (gluten). 

Fiber (indigestible). 

Fat. 

Starch and sugar (principally starch) 
Ash (mineral substances). 


10.50 
12.25 
2.40 
1 *75 
71-35 
i-75 


Ash 
Fat 
Fiber 
mmmm Wafer 

, Protein 


Starch and sugar 


From this table we learn that wheat not only 
contains all the elements of nutrition necessary 
for the growth and sustenance of the body, but 
that these elements are present in the most 
suitable proportions. In fact, the elements in 

wheat, so far as 
they are digest¬ 
ible, exist in 
such propor¬ 
tions as to 
nourish all the 
tissues of the 
body as they 
should be nourished. But eating wheat alone 
is not advisable. It produces too much acid. 
If you will compare the composition of wheat 
with that of milk you will learn that wheat con¬ 
tains a much smaller quantity of fat and a 
much higher quantity of starch and sugar. The 

1 The nickel, or five-cent piece, weighs exactly five grams. It takes about 
150 kernels of wheat, 215 kernels of rice, or 170 kernels of oats to equal the 
weight of a nickel. 


TTT 


v nr 


-r|TT-rr-[- 

*5 50 75 

Average composition of wheat 


1 I ! T 













160 HEALTH READER 

4 

digestive organs of the infant are not suited 
to the digestion of starch. On the other hand, 
they are suited to the digestion of the 
fat which is in milk, and there is a 
comparatively larger quantity of that 
substance in milk. The growing child 
and the grown man can digest starch 
readily, and in the cereals nature pro¬ 
vides a food product containing large 
quantities of starch. Therefore, after 
the period of infancy, cereals are well 
suited to the growing child. 

But it is well to remember that all 
wheat has not exactly the composition 
given in the table. Wheat recently 
harvested contains considerably more 
moisture than is given in the table. 
When wheat has been kept for a long 
time in a dry granary, and especially in 
A wheat a dry country, the amount of moisture 
ta is less than that given in the table. 
Thus whenever the amount of moisture in a 
grain of wheat decreases, the amount of all the 
other ingredients must be greater in comparison 
with the amount of moisture that is left. On 
the other hand, when the amount of moisture 
increases, the amount of all other ingredients 
must be smaller in proportion to the greater 
amount of moisture. 




A STUDY OF THE ARTICLES OF FOOD 161 


How is wheat best used for food? On account 
of its extreme hardness, and the smallness of 
the kernels, there is, as a rule, such difficulty in 
chewing the kernels that it has led to the prepa¬ 
ration of wheat in forms more suitable for eating. 

Old and new ways of grinding grain. In primi¬ 
tive times grain was crushed between stones by 
hand. The natives who inhabited this country 
at the time of its discovery by Columbus pre¬ 
pared their grain in this way. As civilization 



Indian grinding The quern. First form 

stones of grinding mill 


advanced, better methods were needed. This 
led to the development of the quernstone or 
millstone. Millstones are made of hard, gritty 
stone so adjusted that one stone revolves against 
the other, crushing the grain between them. 

In the modern roller mills, millstones are not 
used in grinding grain. In such mills, iron or 
porcelain rollers have taken their place, and 
from grain to finished product the material is 
not touched by hands. 




162 


HEALTH READER 


Grades of flour. There are several grades of 
flour. The words “patent flour” are used to 
name the product of greatest whiteness and 
commercial value, while other names, such as 
Bakers’ Flour, Family Flour, and Red Dog, 
are used for the lower grades. “Red Dog” is 
the name of a flour of low grade, that is, so far 
as color is concerned. Although it is not per¬ 
fectly white, it contains a larger portion of 
important nourishing ingredients than does the 
white patent flour. In the process of milling, 
the germ of the wheat kernel and the hard 
fibrous covering of the kernel, called bran, are 
removed. These materials are then sold sepa¬ 
rately for cattle foods under the names of bran 
and shorts or middlings , and the various' grades 
of flour, made from the inner part of the kernel, 
are sold for use by bakers and housewives. 

Sometimes manufacturers add cornstarch to 
flour, because it is cheaper than wheat and 
makes the wheat go farther. This mixed flour 
is less nourishing than the pure wheat flour and 
should not be used by the housewife. 

How does the milling process affect the nutritive 
value of wheat? The public taste demands a 
flour of extreme whiteness. To meet this demand 
the miller strives to make his flour as white as 
he possibly can. Since the advent of the steel 
roller mill he is able to produce a much whiter 


A STUDY OF THE ARTICLES OF FOOD 163 


flour than he could under the old system of 
grinding the grain between millstones. But the 
wheat germ, which is discarded in the process, 
contains a large quantity of phosphorus and oil, 
and this oil is a food of high value for produc¬ 
ing muscular powei and heat. The bran, which 
is also discarded, is particularly rich in lime, phos¬ 
phorus, and potash, elements of much importance 
in the nourishment of the body. It is also rich 
in protein, but because of its hardness and the 
quantity of fiber it contains, the wheat bran 
cannot be completely digested by the human 
digestive organs. On the other hand, the pres¬ 
ence of the bran, when ground fine with the flour, 
has a most excellent effect in securing a proper 
movement of the contents of the digestive organs. 

A great many of the world’s best students of 
diet believe that whole-wheat flour — flour which 
contains the entire grain finely ground — is 
more wholesome and more nourishing than 
fine white flour. Other experts maintain that 
white flour is more completely digestible than 
whole-wheat flour, and for that reason should 
be preferred. But for growing children es¬ 
pecially, the whole-wheat flour would seem 
greatly to be preferred to white flour. Whole¬ 
wheat flour provides the special nourishment 
needed for the bones and the teeth, a nourish¬ 
ment not to be found in white flour. If young 


164 


HEALTH READER 


chickens are fed nothing but white flour they 
do not grow and flourish. If they are fed 
whole-wheat flour they grow, rapidly and keep 
in excellent health. Even in the case of grown 
men and women, whose bones and teeth are 
already formed, bread made from whole-wheat 
flour is nourishing as well as palatable. 

It is clear, then, that growing children should 
be fed on whole-wheat flour, or some other 
whole cereal, though hard-working men and 
women can occasionally, and even frequently, 
eat the products made from white flour without 
noticeable injury to health. 

Can human beings live on wheat alone? Yes, it 
is possible to maintain life for a long time 
and apparently be well nourished, and yet 
eat nothing but wheat. But the human taste 
and the need for alkali — that is, soda and potash 
— demand a variety of foods in order to keep 
the digestive organs working to the best advan¬ 
tage of the body. In other words, we become 
tired of eating one thing only. We may like 
that one thing very well for a short time, but 
finally, if we have nothing else to eat, we grow 
tired of it. With the exception of milk, the 
food that we would be able to eat alone for the 
greatest length of time is probably wheat and its 
products. What is said of wheat to a certain 
extent may also be said of the other cereals. 


A STUDY OF THE ARTICLES OF FOOD 165 


Next to wheat, what is the most important cereal 
used as food for human beings? Judging from 

its use as a 
food in the 
United States, 
the most im¬ 
portant cereal 
next to wheat 
is Indian corn 
or maiz'e. 

Maize, or corn An ear °f corn 

as it is commonly called in this country, is 
by far the largest cereal crop of the United 
States. For every bushel of wheat grown in 
the United States, about four bushels of corn 
are produced. Corn is used as food for human 
beings in all parts of the country, but the 
amount so used is probably considerably less 
than the amount of wheat used for the same 
purpose. Com is used most extensively as 
food for hogs, horses, and cattle. Practically 
all the hogs raised here are fattened on corn. 

Indian corn is not very extensively used as 
food for human beings in other parts of the 
world. But in the Balkan States and Italy 
in the southern part of Europe where corn is 
grown, its use is increasing. Indian corn is so 
called because it was first found commonly 
cultivated by the Indians in North and South 





i66 


HEALTH READER 


America at the time of the discovery of the 
new world. 


THE AVERAGE COMPOSITION OF INDIAN CORN 


GRAMS 

Weight of ioo grains of corn. 38.00 

PER CENT 

Moisture. 10.75 

Protein. 10.00 

Fiber (indigestible). 1.75 

Fat (oil). 4.25 

Starch and sugar. 71.75 

Ash (mineral substances). 1.50 


What are the chief differences between Indian 
com and wheat? Though the elements that 

make up com 
are apparently 
the same as 
those that go 
to make up 
wheat, there is 
much differ- 


Ash 
Fiber 
■ Fat 

mb Protein 
Water 


^Stcrrch and sugar* 


I 'I IT ITU I | I' I'TTllTH' 

•' 15 , s ° 75 ence both in 

Average composition of Indian corn . 

the quantity 

and in the character of these elements in the 
two cereals. As far as moisture is concerned, 
wheat and corn are almost alike. But corn 
contains much less protein than wheat. The 
average proportions are ten per cent in com 
and about twelve per cent in wheat. There is 
also a great difference in the protein itself. 
The wheat protein consists largely of those 













A STUDY OF THE ARTICLES OF FOOD 167 


elements which, when mixed with water, unite 
to form what is known as the gluten of wheat. 
This gluten makes it possible to knead wheat 
flour into a loaf that will hold together and 
at the same time be somewhat elastic. The 
protein of Indian corn does not have this elastic 
quality. It contains practically none of the 
substance known as gluten. The principal 
protein of Indian corn is known as zein. An¬ 
other striking difference between Indian corn 
and wheat is that Indian corn contains much 
more oil than is found in wheat. 

Thus it is seen that while Indian com is 
highly nutritious, it is distinctly different from 
wheat in its composition. It is much less val¬ 
uable than wheat as a food for young people 
or young animals. Experience has shown that 
if pigs be weaned when quite young, so that 
they get no milk, and are then fed exclus¬ 
ively on Indian corn, they fail to grow; they 
lose flesh, their hair drops off, and finally 
many of them die. This is not the case with 
pigs that are fed on whole wheat. It has been 
found that the chief trouble is in the zein. 
While zein has a high value as a nutritious ele¬ 
ment for grown people, especially when mixed 
with other forms of protein matter, it does not 
promote growth. But if milk is used with the 
corn, then the zein becomes very valuable as a 


i68 


HEALTH READER 


food. Thus if children are given Indian-corn 
products to eat, such products should always be 
served with milk. On a diet of mush and milk 
children thrive. 

If Indian corn, therefore, were the only 
article of food we could get, we should not be 
nearly so well nourished as if wheat were our 
only article of food. 

What is corn meal? Corn meal is the term 
applied to finely ground Indian corn. But the 
particles of corn meal are much larger than 
the particles of white wheat flour. It was a 
very common practice, until within the last 
few years, to grind the entire grain to make 
whole corn meal. Thus the outer envelope of 
the grain,, and the germ, which is so rich in 
phosphorus and oil, were retained in the meal, 
making it more nutritious than if these elements 
had been removed. 

But it has been found difficult to transport 
and keep whole corn meal for any length of 
time, because it molds quickly when moist 
and soon becomes rancid because of the large 
amount of fat it contains. The term “rancid” 
is applied to the sharp, bitter, disagreeable 
taste of an oil which nas partially spoiled. 
For this reason during che last few years millers 
have been grinding corn in the same way that 
they grind wheat flour. They take off the outer 


A STUDY OF THE ARTICLES OF FOOD 169 


hull and remove the germ, thus making a 
corn meal which has much better keeping 
qualities but less valuable nutritive properties 
than the whole corn meal. In order to keep 
corn meal fresh for transportation it is dried. 

The best corn meal, so far as nutrition is 
concerned, is the freshly ground meal made 
from the whole corn grain. 

What are the relations of Indian com to health? 
In many parts of Europe people think that 
Indian corn is not a fit food for human beings. 
We have already learned that corn meal very 
easily molds when moist, or becomes rancid 
because of the large percentage of fat it con¬ 
tains. In this condition corn meal has some¬ 
times been found to be poisonous. Some people 
have claimed also that the skin disease called 
pellagra , which has now secured a foothold in 
our country, is caused by eating musty corn 
meal. However, all evidence goes to prove that 
Indian corn meal does not cause pellagra, but 
that the disease is due to poor nutrition, per¬ 
haps to living almost entirely on carbohydrate 
food. 

From the above it is clear that in its relation 
to health Indian corn has not quite so good a 
record as wheat. But when corn is ground 
whole in order to retain all the elements of the 
grain, and is kept in a proper way, its value as 


170 


HEALTH READER 


a food product is high, especially when eaten 
with milk, or other protein substances such 
as egg, lean meat, or peas and beans. In 
this case it does not in any way tend to injure 
health or induce disease. A more general use 
of Indian corn as food for human beings can 
therefore be highly recommended. 

In what forms is Indian com eaten? Many food 
preparations can be made from Indian corn. 
The simplest of all is “mush,” or “hasty pud¬ 
ding.” Corn meal is also used for 
making bread. In a large part of 
our country, especially in the South, 
bread made of corn is a staple food. 
Corn is also made into hominy, and 
into many varieties of breakfast foods. 
Indian corn can thus be prepared in 
very many forms as food for human 
beings, and when served in a properly 
balanced ration all forms are whole¬ 
some and nutritious. 

Is rye ever used as food for human 
beings ? Only an American would ask 
that question. In Germany, Russia, 
and other parts of Europe, rye is 
used very extensively as food for 
A rye head b uman beings. In many places rye 
bread is much more common than wheat bread. 
Rye is nourishing and wholesome, and may be 



A STUDY OF THE ARTICLES OF FOOD 


171 

V 

used to advantage alternately with white bread. 
Usually rye is cheaper than wheat, and for that 
reason there is generally some economy in using 
it for bread making. 

How does the composition of rye differ from that 
of wheat and com? Rye has about the same 
percentage of protein as wheat, but a much 
smaller content of fat or oil than corn. 


THE AVERAGE COMPOSITION OF RYE 

GRAMS 

Weight of 100 kernels of rye. 2.5 

PER CENT 

Moisture. 10.50 

Protein. 12.00 

Fiber (indigestible).*. 2.35 

Fat (oil). 1.50 

Starch and sugar. 71.75 

Ash (mineral substances). 1.90 

Since rye contains less gluten than wheat, 
and more than Indian corn, rye bread usually 
crumbles more easily than white bread, but holds 

p Fat 
Ash 
Fiber 
wmm Water 
Protein 


Starch and sugar 


together better 
than corn 
bread. In mak¬ 
ing rye bread 
it is advisable 
^ to mix some 
/oo wheat flour 
with the rye so 
as to form a more elastic and more porous loaf. 
Rye is not grown extensively in the United 


i 1 ( 1 1 1 r - ] 1 1 1 1 | r~ 

25 so 75 

Average composition of rye 













172 


HEALTH READER 


States. While the average area on which rye is 
grown is two million acres and the average area 
devoted to wheat is over forty million 
acres, more than one hundred million 
acres are devoted to corn. 

Is barley used as a food for human 
beings? Barley is another cereal that 
is used to some extent as food for 
human beings. But its use for this 
purpose is comparatively small. On 
the other hand, it is grown somewhat 
extensively in the United States for 
cattle food and for making beer. 

Barley that has sprouted is called 
malt . This sprouted barley or malt 
has, above all other cereals, the 
property of converting the starch it 
contains into a kind of sugar, or 
maltose, resembling cane sugar but, in 
many particulars, distinctly different 
from it. Malt makes a good food 
for human beings, . and is used by 
many, especially those whose diges¬ 
tive organs are not in good condition. 
Barley head Many persons who have diseased 
stomachs are unable to digest starchy sub¬ 
stances, but they can very readily take care 
of starch which is already partly digested as 
in the maltose of the sprouted barley. Very 






















A STUDY OF THE ARTICLES OF FOOD 173 


little barley is used directly as food in this 
country. It is sometimes served in soups or 
mixed, finely ground, with infants’ foods. 

What is the average composition of barley? 
Barley very closely resembles the other cereals 
in its composition, but also its protein matter 
differs in character from that of the others. 


THE AVERAGE COMPOSITION OF BARLEY 


GRAMS 

Weight of 100 grains of barley. 4-5 

PER CENT 

Moisture. 11.00 

Protein.^. 10.85 

Fiber (indigestible).*. 3 - 8 5 

Fat (oil). 2.25 

Starch and sugar. 69.55 

Ash (mineral substances). 2.50 


If we compare these figures with those for 
the composition of the other cereals it is seen 
that the amount of protein in barley is greater 
than that in Indian corn and less than that in 

wheat. It con¬ 
tains more fat, 
or oil, than 
wheat or rye, 
but less than 
Indian corn. 
It also has a 
larger content 
Bread 


Fat 

Ash 

Fiber 

Protein 
Water 


Starch and sugar 


T 1-1 " 


75 


I IT 


Average composition of barley 

of mineral substances (ash) than wheat, 
made of barley flour crumbles very easily, and 













174 


HEALTH READER 


for that reason it more nearly resembles com 
bread than wheat bread. 

What is the value of rice as 
a food? Next to wheat and 
Indian corn, rice is the most 
valuable food product among 
the cereals. It is used ex¬ 
tensively by the Oriental or 
Eastern nations, especially 
Japan and China. Rice is 
not widely cultivated in this 
country, the average area in rice in the United 
States being less than a million acres. 

Rice, unlike other cereals, is usually grown 
under water. After it is planted and has be¬ 
gun to grow, water is turned on the fields and 
kept there until near harvest time. Other 
cereals would be killed by such treatment. A 
few varieties of rice grow in dry soil like other 
cereals, but they are not so highly regarded for 
food purposes. Rice, therefore, is grown to 
best advantage in lowlands which can be flooded 
easily, or in regions where abundant water is 
available for irrigation purposes. 

How does rice differ from the other cereals ? 
Rice differs from the other cereals chiefly in 
its high content of starch and its low content 
of protein. In its food value rice resembles the 
potato more closely than it does wheat. 



A STUDY OF THE ARTICLES OF FOOD 175 


THE AVERAGE COMPOSITION OF RICE 


Weight of 100 grains of polished rice. 2.25 

PER CENT 

Moisture. 12.30 

Protein. 8.00 

Fat (oil). 0.30 

Starch. 79.00 

Ash- (mineral substances). 0.40 


These figures show that rice has a low protein 
content, a low fat content, and a low mineral 
content. It is essentially a starch food. 

How is rice prepared for eating? Rice is usually 
prepared for eating without being ground. 
There is such a thing as rice flour, but not a 
great deal of it is used for food. The grains of 
rice, which resemble wheat grains in form, are 
cooked whole. 

It has been a very common practice to 
submit the rice grains to a process of rubbing, 
by means of which the external coating, the 

rice bran, is re¬ 
moved without 
crushing the 
grain. Then, 
Starch I in order to 
make the grain 
still smoother 
and more shiny 
in appearance, it has been customary to 
coat it with finely powdered talcum, using a 


Fat 

Ash 

Protein 
■ Water 


1 | I 1 T " I I I I I I 1 I I TTT 

as SO 75 J 

Average composition of rice 












176 


HEALTH READER 


little sugar or glucose to make it stick. These 
practices are wrong because the consumer is 
deceived by the appearance of the grain, and 
especially because of the injurious effect of 
such rice on the consumer’s health. It has 
been found that people who live almost ex¬ 
clusively on rice treated in this way develop 

a disease of the 
digestive organs in 
some respects re¬ 
sembling anaemia 
(poor blood). This 
disease, known as 
beri - beri, often 
proves fatal. But 
it has been found 
that when unpol¬ 
ished rice is eaten, 
beri-beri never oc¬ 
curs. Also, if the 
rice bran that is 
A dunch of oats - rubbed off in pol¬ 
ishing is given to those who have the disease, 
they recover. 

It is difficult to get unpolished rice in the 
United States. It is not so white nor so 
good to look at as the polished, but it is far 
more pleasing to the taste, more nutritious, and 
more healthful. 



A STUDY OF THE ARTICLES OF FOOD 177 

Are oats used as food for human beings ? > In 

Scotland particularly, and in the United States, 
oats are largely used as food for human beings. 
When the oats, after the removal of the chaff, 
are crushed or ground, the product is called 
oatmeal, and oatmeal is much used for so-called 
breakfast foods; that is, for making the porridge 
or mush to be eaten with milk or cream, partic¬ 
ularly at the morning meal. Large quantities 
of oat products prepared in this way are sold in 
all the markets of the United States. There 
is more gluten in oats than in Indian corn, 
but not nearly so much as in wheat. 

In the United States oats are used principally 
for feeding horses. The acreage planted in oats 
is very large, amounting to almost thirty-five 
million acres every year. 

What is the food value of oats? One hundred 
grains of oats with the chaff on, this being the 
condition in which oats are always sold, weigh 
about three grams. 

THE AVERAGE COMPOSITION OF OATS (unhulled) 


Moisture.’. 10.06 

Protein. 12.15 

Fiber (indigestible). 12.07 

Fat (oil). 4-33 

Starch and sugar. 57-93 

Ash (mineral substances). 3 • 46 


When oats are prepared for food to be used by 
human beings the chaff or outer hull is removed. 








i 7 8 


HEALTH READER 


THE AVERAGE COMPOSITION OF OATS (hulled) 

PER CENT 


Moisture. 7.00 

Protein. 14 .38 

Fiber (indigestible). 1.38 

Fat (oil). 6.00 

Starch and sugar. 69.10 

Ash (mineral substances). .. 2.14 


r~ Ash 
Fat 

. Water 
l. Fiber 
Protein 


Sta rch and sugar 


If you compare the composition of the hulled 
oats with the composition of the unhulled oats 
you will see that the removal of the chaff has 
increased very much the percentage of fat 

and of protein, 
while it has 
diminished to a 
great extent 
the quantity of 
indigestible 
fiber. This is 
highly impor¬ 
tant from the 
point of view 
of food for 
human beings. 
While horses 
and cattle can 
eat unhulled 
/0 ° oats, because 
they are able 


I I II |'l I I I | I I 1 ! | I I I l~ 

2 5 5» 75 100 

Average composition of unhulled oats 

Fiber 

Ash 

— Water 
Fat 

m Protein 

mmm ^Starch. and sugar 


1 1 11 | 1 1 1 1 | r 1 1 1 i'ti 1 1 

O 2$ SO 75 

Average composition of hulled oats 

to digest the chaff, it would be difficult for the 
human stomach to make use of the unhulled oats. 
















A STUDY OF THE ARTICLES OF FOOD 179 


It is also evident that the hulled oats differ 
from other cereals we have studied in the 
larger amount of protein they contain, and 
especially in the amount of fat. Hulled oats 
are to a certain degree similar to nuts in the 
quantity of fat or oil they contain, though the 
quantity is much smaller than that contained 
in nuts. 

Oatmeal is regarded as a wholesome, nourish¬ 
ing food. It is especially valuable for those 
who work hard with their hands, as the oil in 
the oats furnishes a large amount of heat and 
energy. The large quantity of protein which 
is provided takes the place of the protein 
tissues which have been used up during hard 
labor. It also furnishes heat and energy. 
Hulled oats can therefore be recommended as 
a very important human food product. 

VITAMINES 

What are vitamines? By “vitamine” we 
mean certain life-giving elements recently dis¬ 
covered in our foods. It has long been known 
that certain foods seem to do more good than 
could be expected from the amount of nutriment 
they contain. Such foods were known to be 
more wholesome or healthful than others of 
apparently the same nutritive value. . For in¬ 
stance, a certain quantity of protein fed to a 


i8o 


HEALTH READER 



Japanese girls transplanting rice in a 
rice field 


cow in the form of bran produced more milk 
than the same quantity of protein when fed 
in the form of cotton-seed meal. Bran thus 
became a common food in the dairy. It is 
now known that bran is very rich in the ele¬ 
ments known as vitamines. 

How was this discovery made? When the 
Japanese adopted the American habit of using 
polished rice (page 175) a new disease arose 
among the people. They called it beri-beri. 
It was a disease of the digestive organs and 

















A STUDY OF THE ARTICLES OF FOOD 18 


many died from it. By accident a patient 
dying of beri-beri was given a gruel made of 
rice bran. He recovered. This led to the dis¬ 
covery that eating polished rice was the cause 
of beri-beri. 

To what did this discovery lead? It led to a 

study of the bran of other cereals and of the 
vital principles of other foods. It was soon 
found that the bran of all cereals had properties 
in relation to health similar to those of rice 
bran. Other foods also, such as fresh milk, 
were found to have these qualities. The life- 
giving vitamines in milk were found to reside 
particularly in the fat. Cream and butter 
therefore have more vitamines bulk for bulk 
than milk. Fruits, vegetables, and probably 
meats, also contain them. But the article 
which thus far is known to hold the largest 
quantity of vitamines is yeast. 

What is the meaning of the word “vitamine”? 
The word, “vitamine” is derived from the 
chemical term amine. This term is applied to 
a compound containing one nitrogen and two 
hydrogen atoms, which is almost the same com¬ 
bination as in ammonia. Vita is the Latin word 
meaning * ‘ life/’ So the term ‘ * vitamine ’ ’ denotes 
a body resembling an amine which has intimate 
relations to life. But the chemical constitution 
of the so-called vitamine has not yet been 


182 


HEALTH READER 


definitely determined. It is now thought to 
contain phosphorus, and it may contain nitro¬ 
gen and hydrogen also but not in the form of 
an amine. So until more is known about them 
it is best to regard these bodies as activators, 
or substances that are active in aiding the 
process of digestion and nutrition. 

What effect has heat on vitamines? A high 
temperature continued for a long time kills 

some of these 
bodies. Mod¬ 
erately high 
temperatures 
for short pe¬ 
riods diminish 
their activities. 
It is far bet¬ 
ter to use a 
fireless cooker 
than to keep 
the food boil- 
ing over a 
flame for an 
hour or more. 
The tempera- 
A fireless cooker ture of the 

cooker is ap¬ 
plied longer but it is not so high as the tem¬ 
perature reached over the fire. It has long 




























A STUDY OF THE ARTICLES OF FOOD 183 


been known that boiled milk is less wholesome 
than fresh milk. Now we know that this is be¬ 
cause the vitamines have been injured by long 
continued high temperature in boiling. 

What effect have chemicals on the vitamines? 
Mild acids, such as fruit acids, do not injure 
and probably favor the activity of the vitamines. 
On the other hand some alkaline bodies, bicar¬ 
bonate of soda in particular, affect them inju¬ 
riously. For this reason we should avoid adding 
alkaline substances in cooking our food. 

How has it been proved that vitamines can be 
separated from the foods containing them? If 
chickens are fed on polished rice or white 
flour they soon develop a disease resembling in 
some respects beri-beri. They gradually be¬ 
come paralyzed and die. But if fed on water 
extract of bran while they are very sick, they 
do not die. They get well. They will also 
recover if yeast is fed to them. If we now mix 
bran gruel or yeast extract with fuller’s earth, 
filter the mixture to secure the liquid bran or 
yeast extract, and then feed this liquid to the 
sick chickens, we find that it does them no good; 
they die. On the other hand, if the fuller’s 
earth left in the filtering vessel be fed to the 
chickens they get well. This shows that the 
vitamines have all been taken out of the bran 
gruel or yeast extracts by the fuller’s earth. 


184 


HEALTH READER 


Is there more than one kind of vitamine? There 

are at least two classes of vitamines, one soluble 
in fat or oil and the other in water. Neither 
the water-soluble nor the fat-soluble vitamines 
will promote growth when alone. Both must 
be present. Thus there are new reasons for the 
emphasis which has been placed on the impor¬ 
tance of always using milk with cereals. The 
cereals contain the water-soluble vitamines, and 
the milk, the fat-soluble vitamines. Other 
animal fats may contain the fat-soluble vitamine 
but none of them to the extent in which it is 
found in butter. 

Some vegetable oils also contain the fat-soluble 
vitamine in small proportions. Alfalfa and 
cabbage leaves are quite rich in it. 

What are the health lessons of these facts? 
We learn from the discovery of vitamines the 
importance of eating natural foods such as 
whole wheat and other whole cereals, fresh milk, 
fruits, vegetables, and rare-cooked meats. Not 
only are these food products valuable for the 
lime, phosphoric acid, and other minerals they 
contain, but also for the life-giving properties 
(vitamine activators) they contain. We also 
learn that cooking should be conducted at a 
low temperature and not carried to extremes. 
The rare-cooked foods are the most wholesome. 
We learn especially that the over-refining of 


A STUDY OF THE ARTICLES OF FOOD 185 

foods in their preparation, such as bolting the 
wheat and peeling the potatoes, threatens the 
health, happiness, and welfare of our people. 

QUESTIONS TO HELP THE PUPIL 

1. Why is it important to know the average composition 
of a staple food? 2. Why is milk an ideal ration for the 
growing child? 3. What is an ideal or well-balanced 
ration? 4. What simple figures represent the ideal 
proportion of food elements for a growing child as repre¬ 
sented by milk? 5. What cereal has these elements in 
almost the right proportion? 6. What is the objection 
to wheat when eaten alone? 7. What is the average 
composition of wheat? 8. What food element is present 
in wheat in smaller quantities than in milk? 9. What 
element is present in greater quantities? 10. How is 
wheat prepared for food? 11. Describe old ways of 
grinding grain; the new way. 12. What is “patent 
flour”? 13. What part of the wheat kernel is removed 
in modern grinding processes? Why should the germ 
and the fibrous covering not be removed? 14. Why 
should cornstarch not be mixed with flour? 15. What 
is whole-wheat flour? 16. What special nourishment 
does whole-wheat flour provide? 17. For what is corn 
used most extensively in the United States? Is it also 
much used as food for human beings? 18. What are the 
chief differences in the makeup of corn and wheat? 

19. Is zein of corn as nutritious as gluten of wheat? 

20. What is good to mix with com? 21. What is the 

best corn meal? 22. Where is rye commonly used as 
food for human beings? 23. For what is barley used 
most extensively? 24. How is rice grown? 25. What is 

the chief food element in it? 26. In preparing rice for 
the market what bad practice is followed? 27. For what 
persons is oatmeal particularly good? 28. What is a 
vitamine? 29. What effect has heat on a vitamine? 

30. What effect has bicarbonate of soda on a vitamine? 

31. What foods contain the most vitamines? 


7 


XVIII. The Preparation of Bread Foods 


What is bread? By bread we usually mean 
a cereal, ground whole or bolted, which has 
been mixed with water or milk in such a way 
as to form a paste or dough. Yeast or baking 
powder is then usually added; after which the 
.dough is molded or rolled into any convenient 
form and baked on a stone or in an oven until 
the crust is brown. The single word “bread,’’ 
when used in the United States, generally 
means bread made of wheat. The term 
“loaf” applied to bread means a portion of the 

dough formed as 
described above, 
after it has been 
molded into some 
convenient shape 
and baked. 

What is shorten¬ 
ing? The term 
“shortening” is 
applied to a fat 
or oil which is 
mixed with flour 
when a bread 
dough is made, for the purpose of making the 
bread more brittle and more easily broken after 



The seed of the cotton plant yields a 
large amount of yellow oil 



THE PREPARATION OF BREAD FOODS 187 

baking. In addition to this the outside of the 
loaf or the inside of the pan is often greased 
with a fat or oil, so that after the bread is 
baked it will not stick to the pan. Nearly all 
bread has a little shortening added to it. 

One of the most common kinds of shortening 
in general use is lard. Butter also makes an 
excellent shortening material, and is used partic¬ 
ularly in the making of cakes. Vegetable oils 
are used to a large extent for the same purpose, 
especially cotton-seed oil and olive oil. 

Wheat bread is an article of food used at al¬ 
most every table. There is scarcely a single meal 
served in the 
United States 
at which bread 
of some de- - 
scription is not 
eaten. . Wheat hread 

What other cereals besides wheat are used for 
bread? All the cereals can be used for bread 
making. Indian corn is used extensively for 
that purpose, especially in the United States. 
Most of the bread made from Indian corn is 
eaten hot. There is also a bread made of corn 
meal called “pone.” The com pone was a 
staple article of diet among the early settlers 
in our country. It is a wholesome and excellent 
.kind of bread and deserves to be widely used. 




i88 


HEALTH READER 


though at present it is rarely made except in 
the homes of those who live near the frontier 
or in the South. 

Rye is used extensively for bread making in 
foreign countries, but not to a great extent 
in the United States. In many parts of Europe, 
especially in Germany and Russia, rye is more 
commonly used for bread than wheat. Rye 
flour does not make so white a bread as wheat 
flour, but the bread is pleasing to the taste and 
nourishing and can be used now and then in 
place of white bread. Barley, rice, and oats 
are not used to any extent for bread making 
in the United States. 

What are griddle cakes? Griddle or hot cakes 
are a variety of bread made from a batter 
much softer than that used for making bread. 
They are baked quickly on a very hot, smooth 
surface. As soon as one side of the cake is 



A modern kitchen. Making bread in the home 








THE PREPARATION OF BREAD FOODS 189 



brown it is turned and baked on the other side. 
It is customary to make griddle cakes of buck¬ 
wheat flour or corn meal, although white wheat 
flour makes a very good cake, more tough and 
elastic than that made from the other cereals. 

The griddle cake is served regularly at break¬ 
fast in many homes in the United States. It 
is usually eaten with sirup made either from 
the sap of the maple tree or from sugar cane 
or sorghum. Manufactured sirups are made 
largely of a sirupy substance called glucose, 
which is produced from the starch of Indian 
corn or of the potato by chemical treatment. 
Maple sirup is made in large quantities in New 
England, New York, and Ohio. Formerly 
much of it was adulterated, and even now much 









IQO 


HEALTH READER 


larger quantities of so-sailed maple sirup are 
sold than are made of the maple sap. It is a 
common practice among manufacturers to mix 
a little maple sirup with a large quantity of some 
other kind of sirup so as to give the entire mix¬ 
ture a maple flavor. Before the Food and 
Drugs Act became a law these mixtures were 
sold as pure maple sirup. Molasses, which is 
the sirup obtained from sugar in the process of 
manufacture, is also highly prized for eating 
with hot cakes. 

Many food experts object to the use of hot 
cakes for food, claiming that in this condition 
the flour or meal used is not so digestible as 
when made into bread. One of the principal 
objections to hot cakes is that they taste so good 
we eat too many of them. 

Another form of bread is known as cake. 
By the term “cake” is meant some cereal prod¬ 
uct, usually wheat flour, to which considerable 
quantities of sugar, egg, and butter have been 
added, and also usually some flavoring sub¬ 
stances. There are many varieties of cake, with 
which most of you are already quite familiar. 

Is it advisable from the health point of view to 
eat cake? When the cake is made out of 
wholesome materials—good flour, good butter, 
and good eggs—its wholesomeness is assured. 
Unfortunately, cake is usually not a part of the 


THE PREPARATION OF BREAD FOODS igi 

dinner itself, but is served after the dinner 
as dessert. By the time dessert appears the 
ordinary person usually will have eaten all 
that he should eat. The appetizing character 
of cake, its appeal to the sense of taste, and, 
when well made, its general excellent qualities 
make it extremely tempting. We are there¬ 
fore inclined to put into our stomachs large 
quantities of this very nourishing material 
after we have already taken all the nourishment 
we need. For this reason cake becomes a men¬ 
ace to health, not because of what it is made of 
or the way it is made, but because of the cir¬ 
cumstances under which it is eaten. 

Cake contains many nourishing materials. 
Besides the flour, the egg content especially is 
a high-grade nourishing ingredient in cake. 
The butter and the sugar in cake are well suited 
to the development of heat and energy. So, 
if people eat much cake, they should take 
liberal exercise or engage in hard manual labor. 
It is best for a person of quiet habits who takes 
little exercise and does not work hard to let 
cake alone. 

Is cake good for growing children? No, cake 
is not good for children. While it is nourishing 
and valuable as a food, it does not provide the 
food elements in the proportion that is best 
for the child. In cake the heat-forming and 


192 


HEALTH READER 


energy-forming elements are far more abundant 
than they should be in a well-balanced ration 
for growing children. Unfortunately, cake is 
one of the things which the child learns to 
desire more than most other foods, and when 
the taste for it is once formed it is difficult to 
overcome. It is far better to prevent the child 
from forming a habit than to try to control it 
when once formed. Children should not be 
permitted to eat cakes, candies, or artificial 
sweets. Natural sirups and jams and jellies 
made from sound fruits are the only sweets 
they should eat, and these only in small quan¬ 
tities. 


QUESTIONS TO HELP THE PUPIL 

1. What flour is generally used in the United States 
to make bread? 2. Give a definition of bread. 3. What 
is a “loaf”? 4. What is the purpose of mixing oil or 
fat with the flour? 5. What is this fat or oil called? 
6. Why is the inside of the bread pan greased? 7. What 
vegetable oils are commonly used for shortening? 8. What 
is corn pone? Where is it much used? 9. What 
other cereals are used for making bread? 10. What is 
usually served with griddle cakes? n. What law 
stopped the selling of adulterated sirups as pure maple 
sirup? 12. Why are griddle cakes or hot cakes sometimes 

injurious? 13. What is the difference between cake and 
bread? 14. When does eating cake become injurious? 


XIX. Vegetables and Fruits 

What are vegetables? In its widest meaning 
the term “vegetable” includes all the products 
of plant growth. So “vegetable,” in its broad¬ 
est sense, is a term used to distinguish plant 
products from animal products. Both vege¬ 
tables and animals, however, are living organ¬ 
isms, and there is probably no sharp line of 
distinction to be drawn between them. The 
vegetable sometimes seems to merge into the 
animal, or the animal into the vegetable. 

But we have, on the whole, a very distinct 
impression of the difference between a vegetable 
and an animal. A growing vegetable is nearly 
always fixed in its location. That is, it cannot 
move itself from place to place. It cannot go 
out and seek its food; its food must come to it. 
This mode of life is so different from that of 
the animal that we learn to distinguish between 
the two in our earliest years of observation. 
The child of very tender years will be able to 
distinguish between the mouse that runs over 
the floor and the plant that grows in a pot or 
in the yard. 

In a food sense the term vegetable is applied 
to a certain kind of food produced generally 
in the garden, the composition of which is 


193 


194 


HEALTH READER 


characterized by a large percentage of water. 
The vegetables which contain the largest amount 
of water are called succulent , meaning full of 
juice. Among these are the turnip, the radish, 
the carrot, the beet, cabbage, and spinach. 
Vegetables with less water, though still holding 
a considerable quantity, are the white potato 
and the sweet potato. Thus we make a marked 
distinction between the vegetable and the 
cereal, though they both belong to the vege¬ 
table kingdom. In like manner we distinguish 
between the vegetable and the fruit. 

What is fruit? The term “fruit” when ap¬ 
plied to food refers principally to the products 
of certain trees, small shrubs or bushes, and 
vines. The principal fruits used as food are 
apples, oranges, grape fruit, lemons, peaches, 



Growing vegetables at home. A thrifty, well-planned garden 





VEGETABLES AND FRUITS 


i95 


pears, and cherries among the larger fruits that 
grow on trees, and blackberries, strawberries, 
raspberries, grapes, blueberries, and currants 



Children gathering and eating apples 


among the smaller fruits that grow on bushes 
and vines. The distinguishing characteristics 
of fruits are, first of all, their acidity (containing 
acid) and their sweetness. The sugars and acids 
in fruits seem to vie with each other to see which 
will win the upper hand. Sometimes the sugar 
is greatly in excess, as in the very sweet apple, 
and sometimes the acids, as in the cranberry. 
In general the best fruits, judged from their 
taste alone, are those in which the sweet and 
.sour are about equal. 




196 


HEALTH READER 


Fruits are not only pleasant to the taste but 
extremely valuable in maintaining good health. 
When it is possible to secure them, fresh fruits 
should be eaten every day, not only to improve 
the meal but as a safeguard to health. Never¬ 
theless fruits are quite unsuitable for infants, 
and very young children should eat them 
sparingly. The child of five years and over 
may begin to eat fruits in greater abundance. 

The food value of fruits lies chiefly in the 
sugar they contain. There are also valuable 
ingredients in them which minister to the 
mineral needs of the body. All fruits contain 
a little protein, but as a rule, except in the case 
of olives, very little oil or fat. 

How much sugar do fruits contain? The quan¬ 
tity of sugar in fruits varies with the nature of 
the fruit and the degree of ripeness. In ripe 
fruits the quantity of sugar varies from three 
or four per cent to as high as fifteen or twenty 
per cent. Very ripe grapes contain a high per¬ 
centage of sugar. The small fruits, such- as 
berries, contain a low percentage of sugar, 
while apples, peaches, and pears have a medium 
quantity, varying usually from six to twelve 
per cent. 

What kinds of acids exist in fruits? The dif¬ 
ferent varieties of fruits contain different kinds 
of acids. The principal acids in fruits are as 


VEGETABLES AND FRUITS 


197 


follows: malic acid, which gets its name from 
malum , the Latin word for apple, and which 
exists in apples, pears, peaches, plums, cherries, 
and many other fruits; citric acid, which exists 
as the principal acid in the citrous fruits, oranges, 
lemons, and grape fruit, and is so called from 
the family name of these fruits; and tartaric 
acid, so called from the common word “tartar,” 
a term applied to the compound of that acid 
with potash as it exists in grapes. Tartaric 
acid is found particularly in grapes of all kinds 
though it is also present in other fruits. 

Traces of various acids are present in many of 
the fruit products, and it must not be thought 
that only one kind of acid exists in any one 
fruit. Apples, and other fruits of the same 
class, may have traces of other acids besides 
malic. This is also true of oranges and lemons 
as far as citric acid is concerned, and of grapes 
as regards tartaric acid. The acids in fruits 
are generally combined with other substances, 
such as soda, potash, or lime. In most cases 
the acids are combined with potash. 

Should fruits be eaten raw or cooked? As a gen¬ 
eral rule it is best to eat fruits raw. There 
are of course certain dangers connected with 
eating raw fruits which must not be forgotten. 
Raw fruits may contain insects or so-called 
germs that are very dangerous. These evils 


HEALTH READER 


198 

can be removed by careful cooking. Many 
fruits, also, are difficult to chew, as for instance 
certain hard kinds of apples. Cooking im¬ 
proves them in this respect, making them more 
edible (eatable), and more easily digested. 

No hard-and-fast rule, however, can be given. 
Perhaps it is best to say that fruits should not 
always be eaten raw, nor should they always 
be eaten cooked. The judicious housewife will 
know whether a fruit should be cooked or not. 
Some fruits are never cooked, as, for instance, 
citrous products (orange, lemon, and grape 
fruit). 

Are the small seeds of fruits injurious? A great 
many of the fruits, such as berries and grapes, 
have very small seeds. In the case of berries, 
such as strawberries and blackberries, to try to 
take the seeds out would be a hopeless task. 
They may be removed by cooking the fruit and 
then straining the pulp through a fine sieve, but 
they cannot be removed with any success when 
one is eating the fruit raw. There are some 
varieties of grapes in which the seeds are few in 
number. These seeds are also larger than the 
seeds in berries, and may be readily removed. 
By eating one grape at a time the pulp may be 
separated from the seeds in the mouth and the 
seeds rejected. 

Some persons fear to eat small fruits, and 


VEGETABLES AND FRUITS 


199 


especially to give them to children, because of 
the presence of these seeds. It is said, and 
perhaps with 
some reason, 
that the seeds 
may lodge in the 
appendix and 
cause that very 
common and 
much dreaded 
disease, appen¬ 
dicitis. But on 
the whole, these 
fears may be re¬ 
garded as en- The appendix 

tirely groundless. While the seeds of fruits 
may in some cases have been found in the 
appendix when it has been removed, they can 
hardly be regarded as the real cause of the 
trouble. 

In general we may say that the seeds of small 
fruits will be sent out from the body without 
doing any harm. Larger seeds, such as those 
of the apple and the melon, are objectionable, 
but these are not usually swallowed. 

While it cannot be said that to swallow the 
seeds is absolutely without danger, yet the 
chance of harm is so small that we should not 
for that reason refuse to eat these fruits. In 


Ileum or 
small intesti ; 



Vermiform 

appendix, 


200 


HEALTH READER 


the same way, play might be regarded as dan¬ 
gerous. Boys and girls are often hurt, some¬ 
times seriously, sometimes fatally, at play. 
But that is no reason for forbidding children 
to play. The most wholesome of our foods are 
sometimes injurious, either because of an over¬ 
sensibility of our system to their effects or 
because of our eating too much at one time. 
And yet no one would think of excluding such 
foods from our tables. In short, with watch¬ 
fulness and care we may eat all kinds of fruit 
without any bad results. 

QUESTIONS TO HELP THE PUPIL 

i. May any plant be termed a vegetable? 2. What 
is the distinction between a vegetable and an animal? 
3. What is the term applied to vegetables containing 
much water? Name some. 4. Do cereals belong to 
the vegetable kingdom? Are they thought of as vege¬ 
tables? 5. How many fruits can you name that are used 
as food? 6. What fruits grow on bushes? 7. Name 
some fruits that grow on vines. 8. What is the proportion 
of sweetness and acidity in the best fruits? 9. Name 
a fruit in which the acidity is far greater than the sweet¬ 
ness. 10. How old should a child be before eating fruit 
in any quantity? 11. What is the danger of eating raw 
fruits? 12. When does a fruit contain the largest quan¬ 
tity of sugar? 13. Name a fruit with a high content 
of sugar. 14. What percentage of sugar do apples, 
peaches, and pears contain? 15. What are the three 
principal kinds of acid in fruits? 16. Name five fruits 
containing malic acid, three containing citric acid, and one 
containing tartaric acid. 17. Do fruits contain one partic¬ 
ular kind of acid only ? 18. Is there much danger in swal¬ 

lowing small seeds? 19. Should large seeds be swallowed? 


XX. Animal Foods: Flesh, Fish, Fowl, 
Milk, and Eggs 

What are the animal foods? Meat, the flesh of 
animals, or rather, the edible portions of animals, 
is the principal animal food. Milk and eggs 
must also be regarded as animal foods. Milk 
is the natural food of the infant and one of the 
necessary foods for growing children. Even 
grown people, who no longer need to take their 
food in the form of milk, may still get consid¬ 
erable benefit from drinking milk. Milk is one 
of the indispensable foods for invalids. There 
are many kinds of illness in which the patient 
cannot eat ordinary foods. But that patient 
is in a very hopeless state indeed who is no 
longer able to get some nourishment from milk. 
Thus we see that from the very beginning of 
life milk, an animal food, is a natural food for 
man. 

The structure of the teeth and the digestive 
organs of man also lead to a belief that through¬ 
out life he is, to a considerable extent, adapted 
by nature to be a consumer of animal foods. 
Thus from every point of view meat and other 
animal foods in proper quantities and at proper 
times may be regarded as a normal though not 
indispensable food for man. 


201 


202 


HEALTH READER 


What is meant by meat? Meat is the edible 
portion of the bodies of animals. The term 



Tail. 


Soup 


Location of the various cuts of beef 


meat, therefore, includes not only the lean and 
the fat meats of the animal but also the 
nerves, the tendons, and the brain, and all 
the vital organs that are suitable for food. 
Nearly all parts of the body of the meat- 
producing animal are edible. Blood is used 
extensively as food, especially in Europe, where 
it is used in making what is called blood 
sausage. The skin, the bones, the intestines, 
and the lungs, however, are rarely eaten. The 
bones are not generally used as food, simply 
because of man’s inability to chew them. 

The term meat, however, as commonly used, 
refers only to the muscular parts of the animal. 

At what age should we begin to eat meat? 
There are many different opinions concerning 









ANIMAL FOODS 


203 


the age at which children should begin to eat 
meat. To give children a little meat while 
they are still infants is a common practice, and 
it is not unusual to begin feeding children of 
about eighteen months small quantities of 
meat. This is a very unwise thing to do. 
The digestive system of the child, especially 
the very young child, is not well fitted for the 
digestion of meat. 

While there is not much danger in giving a 
two- to five-year-old child a small bit of meat 
once in a while, he can get along very well 
without it. On the whole we may say that 
children under the age of five years should eat 
very little meat of any kind and, better, none at 
all. Between the ages of five and eight years, 
small quantities of the meat of healthy, recently 
killed animals, especially fowls, may be given 
without injury. But cured meats, and meats 
that have been kept in cold storage, should not 



Some common cuts of beef 
a, round roast; b, rib roast; c, loin roast 


be given to children under ten years of age, and 
very little after that age. 



204 


HEALTH READER 


Meats are digested partly in the stomach. 
But since the stomach of the child is adapted 
first of all to the digestion of milk, and since 
the composition of milk is entirely different 
from that of meat, some of the best writers on 
the diet of children say very emphatically that 
meat should not be given to young children. 

When the child begins growing vigorously, 
as he does between the ages of eight and fifteen 
years, meat is especially desirable. After the 
growing age is past we can get along with less 
meat, and when we get old we should, like 
little children, eat it very sparingly. When 
we become very old, we shall find, as is true 
of little children, that milk is again the best 
food for us. 

What are the meats most suitable for food? In 

general it may be said that the meat of all 
animals is edible, but in many cases, through 
religious law or through custom, we reject 
certain animals for food and accept certain 
others. The common meat-producing animals 
are cattle, hogs, sheep, and goats. Among the 
feathered tribes, chickens, turkeys, pigeons, 
partridges, ducks, and geese, both domesticated 
and wild, are used for food. Among the finny 
tribes there are hundreds of edible varieties; in 
fact, there are few fish that are not edible. We 
have, therefore, a wide range of choice, and we 


ANIMAL FOODS 


205 


are generally disposed to divide our meat diet 
into the three classes named—flesh, fish, and 
fowl—meaning by flesh the edible portions of 
cattle, hogs, and sheep. We may also divide 
meat into two classes, red and white, meaning 
by the term meat largely the muscular portions 
of the animal. The animal fats, though they 
should be included under the term meat as well 
as the muscular portion of the animal, are not 
usually so considered. This is not a correct 
view, however, because no matter how lean 
the meat it always contains some fat, and a 
little fat adds much to the flavor and character 
of meat. 

There are certain animals that, although 
edible, yet are not used widely for meat. 
Moses, in the 
book in which 
he advises the 
proper diet for 
his people, per¬ 
mitted the eat¬ 
ing of all ani¬ 
mals that have 
a cloven foot 
and chew the 
cud. This 
would include the cow, the sheep, and the goat. 
So according to the law of Moses pork was 



A steer ready for market 



206 


HEALTH READER 


forbidden, because although the pig has a cloven 
foot he does not chew the cud. By the same 

law the use of 
horse meat was 
also forbidden, 
since the horse 
neither chews 
the cud nor has 
a cloven foot. 
Experience has 
shown, however, 
that horse meat 
is entirely suit¬ 
able for eating, 
and in fact in 

Horse flesh is sometimes used as meat some Countries in 

Europe it is eaten in considerable quantities. 
But the horse is not often used as food until 
the animal is too old. and bony to be good 
for any other purpose. Naturally the meat of 
such an animal cannot be very inviting, and 
for that reason horse meat is not considered by 
most people to be very good. Horse meat is 
not much eaten in the United States, although 
a great deal of it has been shipped out of the 
country for consumption in Europe. 

The hog, however, has come into general use 
as food, and by many persons pork is relished 
more than any other kind of meat, The flesh 





ANIMAL FOODS 


207 


of the hog is especially suitable for curing, far 
more so than that of any other meat-produc¬ 
ing animal. For 
that reason com¬ 
paratively little 
hog meat is eaten 
fresh. The great 
quantities sold of 
smoked and cured 
hams, shoulders, 



A side of bacon 


and bacon prove the truth of this statement. 

On the other hand, most of the meat of beef 
cattle is eaten fresh, much of it being kept in a 
fresh state in cold storage. Considerable quan¬ 
tities of beef, however, are pickled and preserved 
in brine, and this product is known as corned 
beef. Mutton, the flesh of sheep, is also usually 
eaten fresh. Mutton does not readily lend itself 
to preservation, except by cold storage. 

Fish should be eaten in as fresh a condition 
as possible, though it is sometimes necessary 
to keep them in cold storage during transpor¬ 
tation to the place where they are to be sold. 

Fowls are best for food when fresh, although 
immense numbers of fowls of all kinds are kept 
in cold storage, some of them entirely too long 
so far as their tasting qualities and wholesome¬ 
ness are concerned. Yet it is quite true that 
the flesh of poultry and of wild fowl or game if 




208 


HEALTH READER 


Protein 
- Pefu.se 
_ Pat 


Water 


kept for a certain length of time at a low tem¬ 
perature is improved in flavor and taste. And 
it is a well-known fact that beef is much im¬ 
proved in flavor by being kept for from three to 
six weeks at a temperature near the freezing point. 

But to keep articles of food in cold storage 
for an indefinite length of time allows them to 
lose in both taste and quality. It also renders 

the foods less 
wholesome. 
Cold storage, 
therefore, 
should be prac¬ 
ticed with mod- 
eration, and 
rarely should 
articles of food 
be left in cold 
storage for a 
period longer 
than six or nine 
months. 

What is the 
composition of 
meat? Not 
only does the 
meat of differ- 


i i i i | n i i |’i tit p-i i i 

25 fo 75 io< 

Ribs of beef. Proportions of fat and lean 


TT 


Protein 
— Pat 


Water 


TTTT 


I | II I I | I 1 l I | 

o 25 jo 75 10 ° 

Beef tenderloin. Proportions of fat and lean 


Pat 


Refuse 

Protein 


Water 


| 1 1 1 I | 1 1 1 1 | I I I l 

25 jo 75 ro 

Beef round. Proportions of fat and lean 


ent species of animals vary in its composition, 
but also the meat of different animals of the 




















ANIMAL FOODS 


209 


same breed. All meats, however, contain the 
same principal food elements. For that reason 

Fat 

Protein 
Refuse 

---1 Wo, ter 


1 1 11 | r 1 1 1 |"i'i 1 1 i 'l l 1 1 

2$ 5° 75 10 

Leg of lamb. Proportions of fat and lean 


-; rat 

' Rrate 1 n 





Wn tom 

: ; : 

l 1 1 1 | l.l 1 1 | VI 1 1 | l"ll 1 1 


Leg of mutton. Proportions of fat and lean 


it will be nec¬ 
essary to give 
only in a gen¬ 
eral way the 
composition of 
the flesh of ed¬ 
ible animals. 
The edible 
portions of all 
animals consist 
almost entirely 
of fat or oil and 
protein. The 
muscles, the 
tendons, the 
nerves, and the 
brain are made 
up largely of 
0 * * 75 protein. The 

Smoked ham. Proportions of fat and lean q n e S which 

we cannot eat because of their hardness, con¬ 
sist principally of a mineral substance—phos¬ 
phate of lime. They also contain a large amount 
of protein. This is sometimes extracted from 
the bones, making what is known as gelatin. 
But compared with red meat, gelatin is not a 
nutritious food. 



rce/use 

Pmtoi yi 






l 

1 _ Wn tor 



1 | "i" H' 1 | l 1 1 1 ! l 1 1 l | 

II 




















210 


HEALTH READER 


The muscular portions of meat, as we have 
learned, are almost pure protein—that is, they 
consist almost exclusively of substances con¬ 
taining nitrogen. The proportion of protein to 
fat in meat varies greatly, according to whether 
the animal is thin or fat. It varies also accord¬ 
ing to the part of the animal eaten. The sides 
of the hog, from which bacon is made, are com¬ 
posed mostly of fat, with only an occasional 
streak of muscular matter passing through the 
fat. The muscular portions contain more or 
less fat according to the nature of the animal and 
the way it is raised. As a rule, probably half 
of the edible portion of animals is fat. This of 

course includes 
the fat stored 
in various parts 
of the animal’s 
body. Some 
parts of the 
hog are nearly 
all fat. 

It must not 
be forgotten 
that we do not 
eat all the fat 
of an animal in 
the form in which it is originally found. Be¬ 
sides the fat we eat with the meat of the hog, 


Fat 

. Protein. 


iiiir r i 

*s 


Refuse 

Wetter 


~ j~t rn T' T " f r"! 


7S 


Chicken. Proportions of fat and lean 
Fat 

- Protein 
11 ■■■■ 1 Water 

1 1 L .i Refuse 


Mil 


j I I I I | I M I j I I I I 

*5 So IS 10 

Fish. Proportions of fat and lean 













ANIMAL FOODS 


211 


a great deal is made into lard. From fat cattle 
and sheep we get tallow, which is often not used 
for food at all but for soap making and other 
purposes. 

The edible portions of wild game and of most 
varieties of poultry are more lean than fat. 
On the other hand both pork and beef have 
more fat than lean. In fish, also, the amount 
of protein or lean meat generally exceeds the 
amount of fat. 

The data given in the diagrams in this chapter 
refer to meat as purchased and not as prepared 
for the table. They do not include the quan¬ 
tity of mineral matter (ash) or other elements 
which may be present in small quantities. 

QUESTIONS TO HELP THE PUPIL 

i. Name three animal foods. Which one is used 
most? 2. What leads us to believe that animal foods 
are to be eaten by man? 3. What is meat? 4. At 
what age may children begin to eat meat? 5. What 
meat should not be given to children? 6. At what age 
is fresh meat especially desirable for them? 7. What 
are the common meat-producing animals? 8. Into what 
three classes are meats divided? 9. What animal is 
edible though not widely used for meat? 10. What 
kind of meat is usually cured ? 11. What kind is usually 

eaten fresh? 12. Does storing meat for a short time 
at a low temperature improve its flavor? 13. What 
happens when meat is kept in storage a long time? 
14. Of what two food elements does meat consist almost 
entirely? 15. Of what does the muscular or lean portion 
of meat consist? 


XXI. Preserving Foods 

What is the purpose of preserving foods? Nature 
produces foods in greatest abundance at certain 
periods of the year, as during the summer. 
In temperate regions at other seasons, as during 
the winter, under natural conditions no vegetable 
foods or fruits are produced. Though meats, 
fish, and poultry may be had at all seasons of 
the year, yet they are more abundant at certain 
times than at others. For this reason if we had 
no method of preserving foods we might have 
too great a supply of food during one part of the 
year and far too little during another. Hence, 
in order to have a more even supply of food 
throughout the entire year, it is necessary to 
preserve foods. 

Do all foods need preserving? There are some 
foods which may be safely kept a long time, 
since their natural qualities make them resist 
decay. Good examples of these foods are the 
ripened kernels of wheat, corn, oats, rye, and 
other cereals. When kept dry and free from 
insect pests, these foods may be stored for a 
year or longer without losing in taste and flavor 
or becoming less wholesome. In fact, cereals to 
a certain extent improve with age. They are 
better for milling and for general handling after 


212 


PRESERVING FOODS 


213 


they have been kept a few months than they are 
immediately after being harvested. This is 
because they dry out and thus become hard 
and better able to resist decay. 

Succulent vegetables may also be kept for a 
considerable length of time without loss of 
quality. For instance, potatoes, turnips, beets, 
radishes, and cabbages, and fruits of many kinds, 
such as apples, pears, and oranges, may be kept 
for many months if put in a cool, dry place 
and protected from freezing. But vegetables 
do not retain their good qualities nearly so well 
as do the cereals, and fruits also are better if 
not kept too long. Certain fruits, such as 
strawberries, raspberries, and blackberries, keep 
only a few days. Peaches and apricots keep for 
a comparatively short time. Many foods which 
are eaten before they are ripe, such as green 
com, will keep only a few hours without losing 
in taste and quality. Green com and green 
peas lose very rapidly in quality after having 
been plucked from the stalk. If you wish to eat 
green corn or green peas the best plan is to go 
into the garden or field, gather the vegetables, 
and cook them immediately. In this way you 
get these delicious foods with their greatest 
sweetness and tenderness. 

Flesh food, whether of domesticated animals, 
poultry, wild game, or fish, loses rapidly in 


214 


HEALTH READER 


quality, especially in warm weather. It may be 
said to begin to lose in quality from the moment 
the animal is slaughtered, although it may be 
many hours or even days before this becomes 
evident in the taste and the odor of the article. 

What methods are used in preserving perishable 
foods? There are several well-known methods 
of preserving perishable foods, some of which 
are good and others highly injurious. Inasmuch 
as it is the large amount of water in foods that 
promotes spoiling, one of the oldest and best 
methods of preserving these products is by 
drying. Fruits may be spread in the warm 
sun and in a few days dried sufficiently to keep 
a long time. In localities where the air is very 
pure and dry, as in Arizona and New Mexico, 
fresh beef hung up on a pole is dried so quickly 

that it will keep 
its qualities for 
months. This 
product is called 
“jerked beef/' 
Dried beef, 
well known in 
commerce, is 
produced by ex¬ 
posing the meat, 
after it is properly salted, to artificial heat or 
to the natural drying process of the air, 





PRESERVING FOODS 


215 


Usually, artificial heat is used in drying fruits 
that spoil quickly; that is, the fruits are sub- 



Drying raisins in trays in the open air 


jected to hot air at a temperature that will not 
char or bake them, but yet dry them out rapidly. 
The air is warmed by a furnace built for that 
purpose. This air is then conducted over the 
fruit to be dried. Hot air absorbs a great deal 
more moisture than cold air. 

In this country the principal foods preserved 
by drying are the fruits. Annually vast quan¬ 
tities of peaches, apples, pears, apricots, and 
other fruits are dried. Grapes are also dried, 
the resulting product being known as raisins. 
One of the greatest centers of the dried-fruit 
industry is in California. There the long, hot 
days and periods of dry weather make it possible 
to dry almost every kind of fruit by means of the 





2l6 


HEALTH READER 


sunshine alone. In rainy countries this drying 
process is difficult because of the rainstorms 



Women preserving fruit by canning 


which come often and with little warning. 

Vegetables of various kinds, too, are dried, 
but this industry is not so great as fruit drying 
because of the difficulty of restoring the dried 
vegetable to its natural condition when prepar¬ 
ing it for eating. Potatoes, sweet corn, and 
various succulent vegetables have been dried 
successfully, but to no such extent as the fruits. 

What is another good method of preserving per¬ 
ishable foods ? More than a hundred years ago 
a French chemist by the name of Appert dis¬ 
covered that if perishable foods are heated to 
the temperature of boiling water and kept so 
for a certain length of time, and are then 

































PRESERVING FOODS 


217 


inclosed in air-tight packages, they will keep 
indefinitely. This was the beginning of what 
is known as the canning industry. In canning 
perishable foods, such as vegetables, fruits, 
meats, milk, and other products, they are heated 
to or above the temperature of boiling water for 
varying lengths of time and then placed in con¬ 
tainers which are sealed to keep out the air. 
This is one of our great industries. The articles 
canned in this country are chiefly fruits, toma¬ 
toes, green corn, peas, beans, meats, and milk, 
although almost every kind of food may be pre¬ 
served in this way. 

What food products are commonly kept in cold- 
storage ware¬ 
houses ? This 
is a very im¬ 
portant ques¬ 
tion and one 
concerning 
which every 
one should 
have exact 
information. 

The common 
foods kept in 
cold-storage 
warehouses are, first, meats of all kinds, poultry, 
fish, and game. In addition to these articles 



Interior of a cold-storage warehouse 


8 






























2 l8 


HEALTH READER 


the product most commonly placed in cold stor¬ 
age is eggs. Fruits of all kinds, particularly 
apples, are also placed in cold storage in great 
quantities. 

At what temperatures are these foods kept? 

Poultry and fish are kept at a temperature much 
below the freezing point of water. The result 
is that the poultry and the fish become frozen 
solid and remain in that condition in the cold- 
storage warehouse until sent to market. Some¬ 
times meat also is frozen; for instance, much of 
the fresh meat shipped from Australia to Great 
Britain. But most beef is kept at a temperature 
just above the freezing point. Eggs are kept 
at a temperature at which they will just escape 
freezing, the nearer to the freezing point the 
better. Milk and cream also are kept at tem¬ 
peratures just above the freezing point. 

How long should foods remain in cold storage? 
There is only one answer to this question— 
just as short a time as possible. There are cer¬ 
tain kinds of foods which need to be kept in cold 
storage only for the length of time necessary to 
transport them to the place where they are to 
be sold. Such foods as these are fish and 
poultry. The fishing season extends over nearly 
the entire year, so it is possible to secure reason¬ 
ably fresh fish at almost all seasons. Eggs and 
chickens are more abundant in the spring and 


PRESERVING FOODS 


219 


early summer than at any other time, but by 
care in arranging hatching periods, which is 



made possible by modern methods of poultry 
raising, young chickens may be produced at all 
seasons of the year. Poultry therefore need be 
kept in cold storage only long enough to trans¬ 
port it and sell it. 

Butter is another product which is more 
abundant, in the spring than at any other season. 
Hence large quantities of butter are put into 
cold storage in the spring to be sold during the 
following winter. The abuse of cold storage lies 
chiefly in the practice of keeping these products 







220 


HEALTH READER 


— fish, poultry, butter, and eggs—for too 
long a time in order to influence prices or for 
other reasons. One 
great need in regard to 
cold storage is that 
every food product kept 
in storage longer than 
the time necessary to 
transport and sell it, 
should be so marked 
that the buyer may 
know what he is get¬ 
ting and how long it 
has been in storage. 

Another abuse of cold storage consists in 
storing products that have already begun to 
decay. Of course articles in such a condition 
can never be improved. By awakening the 
public to the danger of such practices they can 
be stopped. 

Is there any other method of preserving foods? 

Yes, one of the most important methods of 
preserving foods has not yet been described. It 
may be termed the “pickling method.” This 
method is used in preserving both meats and 
vegetables. We are all familiar with the ordi¬ 
nary pickles of the household, made chiefly from 
the cucumber. The ordinary vegetable pickle 
is usually preserved by means of salt, sugar, and 



Churning butter 



PRESERVING FOODS 


221 


vinegar. In addition to these three articles 
many spices are used in pickling, largely because 
of the flavor or taste which they give to the 
product. 

The principal material used in the pickling 
of meats is salt. The product known as “mess 
pork,” of which great quantities are used, is 
hog flesh preserved principally in salt, or in 
a strong solution of salt called brine. In the 
preparation of pork for bacon or ham, the flesh 
of the freshly slaughtered hog is first treated 
with salt in such a way as to make the salt spread 
as nearly as possible through every part of the 
meat. When pickling thick pieces of meat, 
the salt is injected into the meat with a syringe, 
as well as rubbed on the outside. 

After the salt has thoroughly spread through 
the meat it is put through another process, 
known as curing. The bacon and the hams 
and shoulders are hung in a room filled with 
smoke, produced usually by burning green 
wood, preferably hickory or oak. In the old- 
fashioned method of curing, this process is 
repeated once a month and the method of curing 
is slow. But in the great packing houses the 
hams and bacon are placed in closed chambers 
at a high temperature and large quantities of 
smoke forced into them, so that the smoking 
will occupy only a few hours. That is one 


222 


HEALTH READER 


reason why the products prepared in the pack¬ 
ing houses never reach the grade of excellence of 
the products prepared in the old-fashioned way. 

In order to preserve the red color of meats 
saltpeter is often used in small quantities at 
the time of salting. Saltpeter has the property 
of producing a bright red color in the muscular 
fibers which closely resembles the natural color. 
Thus when ham or bacon is cut the muscular 
fibers are a bright red and look like fresh meat. 
This practice should not be permitted for two 
reasons: first, because the color is deceiving; and 
second, because chemicals of this kind, if used 
in any considerable quantity, have a distinctly 
harmful effect on the health. 

Beef is preserved in the same way as pork, 
although not a great deal of it is smoked. It 
is usually preserved in brine, and is then called 
“corned beef.” Common salt and saltpeter are 
the chief ingredients used in corning beef. 

What is catchup? One of the preserved vege¬ 
table foods in common use is known as catchup. 
Catchup is made usually of tomatoes to which 
vinegar, salt, spices, and sugar are added. 

To what is the color of catchup due? In catch¬ 
up that is properly made the red color is due 
solely to the tomatoes. For this reason ripe red 
tomatoes are used. Whenever catchup is arti¬ 
ficially colored, which at the present time is 


PRESERVING FOODS 


223 


not often the case, you may be certain that the 
tomatoes used were not of the proper color or 
degree of ripeness. If green tomatoes have 
been used the 
catchup will not 
have the right 
color. Only red, 
ripe, perfect to¬ 
matoes should 
be used in the 
manufacture of 
catchup. In 
order to get the 
best color the 
catchup should 
be made quick¬ 
ly. This is pos¬ 
sible in large 
factories which 
have the ma¬ 
chinery and 
equipment for 
the process. For A tomato plant with fruit 

that reason the catchups made by large manu¬ 
facturers have a more decided red color than 
those made at home. 

What keeps catchup from spoiling? Catchup is 
kept from spoiling by being heated to a high 
temperature when made. If it is of the proper 





224 


HEALTH READER 


density, that is, if it has from twenty to thirty 
parts of solid matter to one hundred parts of 
liquid, and if it contains the proper 
quantity of sugar, spices, and vine¬ 
gar, the catchup will keep for a 
considerable length of time after 
the bottle is opened. Catchup 
should not be used after the bottle 
has been opened more than three 
or four days, unless it is kept in 
a refrigerator. 

What are some of the adulterations 

A bottle of of catchup ? Sometimes catchup 

catchup * s ma( j e 0 f fho cores and skins of 

tomatoes, or of green and imperfect tomatoes, 
or by mixing pumpkins and the cores and skins 
of apples with the tomatoes. Such adulterated 
catchup should be avoided. Catchup is preserved 
sometimes by adding benzoate of soda, a harmful 
substance, but that practice is disappearing. 

What is jelly? “ Jelly” is the term applied to 
the substance derived from boiling a fruit juice 
to which a certain amount of sugar has been 
added. This substance after cooling has the 
property of hardening to an elastic, jelly-like 
mass. Among the fruits used for making jellies 
are berries, apples, plums, and grapes. Chil¬ 
dren should not eat jelly to any extent until 
they are old enough to control their appetites. 




PRESERVING FOODS 


225 


Should preserved foods be entirely excluded 
from our diet? The preservation of food prod¬ 
ucts is an extensive industry and one of great 
value and importance. But there is no food that 
is not to a certain extent injured in quality by 
the process of preserving. However, though 
there may be a slight danger t.o health from the 
salt, the vinegar, and the spices used in pre¬ 
serving, the well-known preserved products 
need not for that reason be entirely excluded 
from our food lists. 

QUESTIONS TO HELP THE PUPIL 

i. Why do we preserve foods? 2. Name some foods 
that are more resistant to decay than others. 3. How 
must succulent vegetables be kept to preserve their 
good qualities? 4. Name a vegetable and a fruit that 
will keep only a very short time. 5. What is an old 
method of preserving fruits and meat? 6. What is 
“jerked beef”? 7. Which state is a great dried-fruit 
center? 8. What method of preserving foods was dis¬ 
covered by Appert? 9. What is meant by cold storage? 
10. At what temperature are poultry and fish kept? 
Eggs and milk? 11. What is the danger of cold storage? 
12. What is the longest period any food product may be 
kept in cold storage ? 13. How are vegetables ‘ 1 pickled ’ ’ ? 

14. What is added to give flavor? 15. How is meat 
pickled? 16. What is brine? 17. What is the process 
known as “curing”? 18. What substance is often used 
to color cured or pickled meats? Why is this practice 
condemned? 19. What is catchup? How is it kept from 
spoiling? 20. Explain how catchup is sometimes adul¬ 
terated. 21. What is the effect of preserving treatment 
on any food? Should we let this keep us from using 
such foods? 


XXII. Nuts as Food 


What is the food value of nuts? The food 
products known as nuts are the fruits or seeds 
of certain trees and bushes. They are composed 
chiefly of protein and fat, and so have a high 
food value. All nuts also contain a considerable 
quantity of sugar, but only a few, such as the 
chestnut, contain much starch. 

Are nuts better for food when raw than when 
roasted? The answer to this question is both 
yes and no. Many of our common nuts are 
excellent in the raw state. Especially is this 
true of walnuts, hickory nuts, and pecans, all 
of which belong to the same general family. 
The flavor and character of nuts of this kind 
are not improved by heat. But there are other 
nuts which are much more pleasing in taste and 
flavor after being roasted than before. Among 
these the most important are the peanut and the 
chestnut. Both of these nuts are greatly im¬ 
proved by roasting. In fact, the peanut is 
rarely, if ever, eaten raw. It then has a harsh, 
bitter taste quite different from and much less 
agreeable than that developed by roasting it. 
The chestnut is agreeable to the taste both in 
its raw and in its roasted state, but is con¬ 
sidered much more agreeable when roasted. 


226 


NUTS AS FOOD 


227 



A white oak tree 


What are some of the principal varieties of nuts ? 

It is not necessary to tell the boys or girls who 
live in the coun¬ 
try much about 
the common kinds 
of nuts. You can¬ 
not go into the for¬ 
est in the autumn 
without finding 
them. The nuts 
found most com¬ 
monly in the forest 
are those that grow on oak trees. They are 
called acorns. The oak is one of the most ma¬ 
jestic trees of our forests. Oak trees live to a 
great age and in favorable soil and climate grow 
to a great size. The acorn is a beautifully 
formed nut, growing out of its 
cap in the interesting way you 
all know. Acorns are gathered 
for food by squirrels and birds. 
Hogs are particularly fond of 
them. In the autumn many a 
farmer turns his hogs into his 
oak forest, where they fatten 
on the acorns. 

Another nut found on forest 
trees is the beechnut. In shape 
Acom fruit and leaf it is triangular like a grain of 



228 


HEALTH READER 


buckwheat. It does not grow so large as the 
acorn, but it is much more pleasing to the taste, 
although it is rarely found in the markets. 
Only those children who live near a beech forest 
really understand what excellent eating beech¬ 
nuts are. 

A third important nut of the forest is the 
hickory- nut. Hickory nuts are justly classed 
as among the best flavored of all nuts. 

The pecan, which grows only in the southern 
part of our country, is another of our finest nuts. 
It is not found to any great extent north of 
Tennessee and North Carolina, and grows best 
south of these states, in Georgia, Alabama, 
Louisiana, Mississippi, South Carolina, and 
Florida. The pecan is now T being cultivated in 
large orchards in various parts of these states. 
The cultivated varieties are large, with very 
thin shells and large kernels. The pecan is a 
great favorite with a large class of people. 

Many other kinds of nuts grow wild, and 
among these one of the best is the hazelnut. 
The black walnut also, with which the Ameri¬ 
can boy is acquainted, was a very common nut 
until our walnut forests began to disappear. The 
black walnut tree was always to be found on 
very fertile land, in this respect resembling 
the maple. In clearing the land for farms, 
the early settlers preferred the richest lands, and 


NUTS AS FOOD 


229 


so quite naturally the walnut and maple trees 
were the first to disappear. No longer are the 
farmer boy's hands 
stained with the walnut 
juice, once so common 
a sight during walnut¬ 
gathering time in October 
and November, after the 
frosts. From the outer 
covering of the walnut our 
grandfathers and grand¬ 
mothers extracted a 
stain which they used in 
dyeing. 

The butternut is an elongated walnut with 
much the same taste and character as the 
walnut. The English walnut is a thin-shelled, 
cultivated walnut, which differs in many ways 
from the wild walnut of the American forests. 
All these different varieties of nuts grow on 
trees, with the exception of the hazelnut, which 
grows on a shrub or bush. 

What is the difference between the peanut and 
the nuts that grow on trees? The peanut is the 
fruit of an annual plant. Instead of growing 
above the ground as other nuts do, it grows 
underground. The flowers from which the 
peanuts develop grow above ground on long, 
bending stems. These stems bend to the ground 



HEALTH READER 


23° 

and burrow under the surface, where the nuts 
form and ripen. The peanut grows best in the 
southern states of our coun¬ 
try, being raised in great 
quantities in southern Vir¬ 
ginia, North Carolina, and 
Tennessee. 

The peanut is used prin¬ 
cipally as a food for human 
beings. It is always roasted, 
a process which, we have 
already learned, improves 
its taste and aroma. The 
peanut is one of the im¬ 
portant features at open-air 
meetings, picnics, and 
public gatherings of all 
kinds. The baseball game, 
the football game, the horse race, and the 
circus would hardly seem real if the noisy 
venders of peanuts and popcorn were not 
present to satisfy the popular demand for these 
products. Peanuts are a wholesome and nutri- 
• tious food product, but are usually eaten in such 
large quantities as to unbalance the ration. By 
this is meant that too great a quantity of pro¬ 
tein and oil in proportion to other food elements 
is taken into the body. Peanut butter is made 
by crushing roasted peanuts. 



A peanut plant 



NUTS AS FOOD 


231 


What relations have nuts to health? When used 
in the proper quantity, nuts are a valuable 
addition to our food supply. Nuts may also 
be used to advantage because of their direct 
benefit to the health. In this respect they may 
be classed with fruits, being not only food 
products but health-food products. Because of 
its oily nature the nut acts as a natural laxative, 
tending to correct constipation, a common con¬ 
dition among people of all ages and occupations. 
This fact, however, does not justify the fads of 
some food experts who tell us to eat nuts only. 
It is more than likely that it would be injurious 
to health to exclude from the diet all food 
products except nuts. But a more widespread 
use of nuts as food is advisable for the best 
interests of health. It is also better to eat a 
few peanuts once every day than to eat a large, 
quantity one day and none at all for a week. 

Are there any dangers in eating nuts? It has 
already been pointed out that by eating nuts 
to excess you may take in more protein, and 
especially more oil, with your food than is 
advisable. In addition to this, you must be 
careful when eating raw nuts to avoid eating 
insects and their eggs. The nut is an ideal 
food for certain insects. The mother insects 
understand this and that is why they bore 
through the shell and lay their eggs inside the 


232 


HEALTH READER 


nut. Certain wild nuts, especially the chestnut, 
are apt to be infected in this way. Roasting the 
nuts is a complete guarantee against the danger 
of taking the living eggs into the stomach. 
Still, many of us do not like to eat worms, even 
though they are well cooked. 

Fortunately, most of the nuts we eat are 
easily inspected, and the worm is always honest 
enough to make itself known when the shell of 
the nut is removed. If the nut has been infected 
the results are always visible, and with a little 
attention it is easy to guard against danger from 
this source. Moreover, the danger is very slight, 
since it is not at all likely that any of the 
insects or the eggs found in nuts will continue 
to develop in the intestines. Yet such things 
sometimes do happen, especially in children. 
Various sorts of worms infect the alimentary 
canal of young persons. Some of them may be 
harmless, but all are disagreeable and some, 
like the tapeworm, are positively dangerous. 
None of these insect pests are natural to the 
intestine. They are all introduced from with¬ 
out, usually in the form of eggs and generally 
with our food. 

Hence cooking, while it may injure the taste 
of some foods, prevents insect infection, which 
is always more or less threatening to health. 
Therefore children eating nuts should carefully 


NUTS AS FOOD 


233 


inspect them beforehand and reject all that 
show any evidence of insect ravages. 

When should nuts be eaten? As a rule, nuts 
should be eaten at mealtime. As a matter of 
fact, however, a large proportion of the nuts 
that are eaten, especially by children, are 
taken between meals. This is not especially 
objectionable if only a few are eaten, but to 
eat large quantities of nuts between meals is 
dangerous, not because they are nuts but 
because fresh quantities of undigested foods 
are added to those that are partly digested. 

QUESTIONS TO HELP THE PUPIL 

1. Of what food elements are nuts chiefly composed? 
2. Why are peanuts better after roasting? 3. How does 
the peanut taste when it is raw? 4. Why is it better 
to roast chestnuts? 5. Name all the kinds of nuts that 
you know. 6. What kind of nuts do hogs like? 7. 
What kind do you like best? 8. For what was the 
outer covering of the black walnut used in early days? 
9. How do peanuts grow? 10. Why should we avoid 
eating large quantities of peanuts or other nuts? 11. Of 
what should we be careful when eating nuts? 12. When 
should nuts be eaten? Why not between meals? 


XXIII. Beverages 


What kind of beverages should the child use? 

Children should drink nothing but pure drink¬ 
ing water or pure milk. All other beverages 
are unnecessary, habit-forming, and injurious. 

What is pure drinking water? Pure drinking 
water is not exactly the same thing as pure 
water. Pure water is water that contains 
nothing besides water. It is very difficult to 
obtain. The ordinary distilled water used by 
druggists cannot be said to be entirely pure. 
Distilled water, moreover, is not the best drink¬ 
ing water for children. For them the ideal 
drinking water is spring or well water that has 
not been infected by water pouring directly 
into the well or spring from the surface of the 
ground near it. The ideal drinking water 
contains a certain quantity of the mineral sub¬ 
stances present in the soil through which the 
water percolates or oozes on its way down. 

How much mineral matter is found in good 
drinking water ? The quantity of mineral matter 
in water varies with the character of the rocks 
with which the water comes in contact as it 
percolates through the earth. Limestone is 
much more readily dissolved than sandstone, 
hence lime is usually the chief mineral found 


234 


BEVERAGES 


235 


in water. When spring water does not pass 
through limestone, other mineral substances 
are found in it, 
but usually not 



in large quanti¬ 
ties. When small 
quantities of 
mineral matter 
are present the 
water is said to 
be “soft”; when 
large quantities 
of mineral, espe¬ 
cially of magnesia 
and lime, are 
present, it is said 
to be “hard.” 


An old-time well-sweep 


Which is more wholesome to drink, hard water 
or soft water? Usually a soft water that con¬ 
tains just the proper proportion of mineral 
matter is best for drinking. If the water is too 
hard it may contain more mineral substances 
than are necessary for good health. 

Can hard water be softened ? Hard water may 
be softened in two ways. In hard water there 
is often a large amount of carbonic acid holding 
a certain quantity of minerals in solution. If 
the water is boiled the excess of carbonic acid 
is driven off and the minerals which were held 


236 


HEALTH READER 


in solution by the excess of carbonic acid are 
released and deposited on the bottom and sides 
of the vessel in which the water is boiled. Thus 
by the simple process of boiling, some hard 
waters are rendered more or less soft. Tea¬ 
kettles used for boiling hard water become 
covered inside with a mineral deposit. If hard 
water does not soften by boiling, it can be 
softened by adding washing soda, borax, or 
ammonia. But water softened in this way 
must not be used for drinking. 

What is the best location for a spring ? We have 
no choice in the location of springs. Nature 
has decided that for us. But we may choose 
between springs, when more than one is avail¬ 
able. In selecting a spring as a source for 

drinking water 
the locality 
from which the 
waters are be¬ 
lieved to come 
should always 
be carefully 
inspected. A 
spring on an 
uninh abited 

A hillside spring hillside Or 

mountain provides an ideal drinking water, cold 

and clear and without injurious substances. 




BEVERAGES 


237 


But the water in a spring may really come 
from a much greater distance than we suppose. 
So it is not always possible by inspecting the 
immediate neighborhood of a spring to deter¬ 
mine the character of the soil through which the 
waters pass. For this reason we should call on 
the geologist, who will find out for us how the 
layers of rock are slanted in order to discover 
from which direction the water comes. 

The only way we can be sure about the 
character of water is to have it carefully ex¬ 
amined. The chemist will tell us what minerals 
the water contains, and the bacteriologist will 
tell us all about the bacteria or organisms which 
may be found in it. Spring water coming from 
uninfected localities will be almost sterile; that 
is, it will contain almost no living organisms. 
The smaller the number of organisms or bacteria 
a water contains, the better it is for drinking. 

The wise general does not permit his soldiers 
to drink water in an enemy’s country until 
it has been analyzed. During the Japanese- 
Russian war chemists and bacteriologists were 
sent ahead of the Japanese troops in Russia to 
put up notices as to the waters that were good 
to drink and those that were to be avoided. 

How much water should we drink? The body 
requires a greater quantity of water than 
we can get indirectly as a part of the foods 


238 


HEALTH READER 


which we eat. So the human animal needs 
to take a good deal of water in addition to the 
water in the food he eats. The amount needed 
varies with the character of his food, the 
temperature of the atmosphere in which he 
lives, and the amount of physical exercise he 
gets. The drier and saltier the food, the greater 
the quantity of water needed. The higher and 
drier the atmosphere, the greater the quantity 
of water needed; and the more vigorous the 
exercise, the greater the quantity of water 
needed. Thus a person who eats very dry, 
salty food in hot weather, and at the same 
time engages in vigorous manual labor or vio¬ 
lent exercise, requires most water. It follows 
that we need the greatest quantity of water in 
summer and the smallest quantity in winter. 

Though much water is formed from the oxi¬ 
dizing, or burning, of the foods in the body 
(Part I, page 90), there is still not enough for 
the needs of the body without drinking ad¬ 
ditional quantities. 

When should we drink water? A good rule to 
follow is to drink when thirsty. Another good 
rule is to drink a certain quantity of water at 
regular intervals, whether thirsty or not. For¬ 
merly it was quite generally believed that we 
should not drink with our meals. This idea was 
a valuable one, although recent investigations 


BEVERAGES 


239 


have shown that, if the food is very dry and is 
not well chewed, a considerable quantity of water 
may be taken at mealtime and not only not 
interfere with digestion, but even promote it. 

As a general rule it is best not to drink 
water when eating. During the process of chew¬ 
ing, the salivary glands are actively engaged in 
secreting saliva and mixing it with the food, a 
process useful to digestion, especially of starchy 
foods. To drink water while we are chewing 
our food makes the salivary glands less active 
and so the flow of saliva is diminished. Thus, 
although the water in itself is not harmful, 
it interferes with the secretion of saliva and its 
admixture with the food, a process that is neces¬ 
sary for good digestion. Yet at the same time 
it is well to remember that the proper digestion 
of the food in the stomach and in the small 
intestine is checked if the contents of the stom¬ 
ach and the intestines are too dry. So it seems 
that the best plan is to drink water rather freely 
either before or directly after eating but to 
refrain from doing so during the meal in order 
that the salivary glands may properly perform 
their function. 

At all events, we should not neglect to drink 
water. If we eat five pounds of food a day, 
including water as food, nearly four pounds of 
it should be water. 


240 


HEALTH READER 


When should we drink milk? Young children 
and growing children should drink milk at 

least three times 
a day. Milk is 
not only a 
beverage but a 
highly valuable 
food. It CQn- 
tains about 
eighty-seven per 
cent of water; 
to that extent 
it is a beverage. 
But the other 
thirteen per cent 
is made up of 
certain food ele¬ 
ments so ideally 
balanced that 
all the tissues of the body are nourished with 
the best possible benefit. 

When we see a boy sitting at a table eating 
good brown bread made of whole-wheat flour, 
and drinking pure, clean, fresh milk from 
healthy cows, it makes the heart rejoice, because 
we know that boy is getting the best possible 
food and in the very best form. When he adds 
to these things vegetables, fruits, and nuts, we 
may be certain that he has all he needs to 




















BEVERAGES 


241 


nourish his body and properly promote growth. * 

Too often children, after the years of infancy 
and early childhood are past, give up the 
habit of drinking milk. It would be better if 
the habit of drinking milk were fostered rather 
than abandoned. A quart of milk a day is 
little enough for a growing child. But pure, 
clean milk is an expensive food. Happy indeed 
the family that can keep a cow, especially so 
if careful attention is paid to keep her healthy, 
clean, and well fed. 

What are the effects of sour milk on health ? 

Most experts believe sour milk to be wholesome, 
and it is especially recommended in certain 
irritated conditions of the stomach when ordi¬ 
nary fresh milk cannot be taken. Many 
persons believe that the constant use of sour 
milk, either buttermilk or ordinary sour milk, 
is not only healthful but will make people 
live longer. While sour milk is wholesome, 
and to that extent helpful in prolonging life, 
it is impossible to believe that a diet of sour 
milk will relieve us of all the ills that neces¬ 
sarily attend old age. Perhaps people who need 
more acid food might go a much longer way 
toward the century mark if they drank butter¬ 
milk or sour milk more freely. 

Few people live to be a hundred years old, 
no matter what they eat or drink, but many 


242 


HEALTH READER 


of us could come nearer, to living one hundred 
years if we were more careful of what we eat 

and drink. 

What is coffee ? 
Coffee is the fruit 
of a small tree. 
The coffee tree is 
larger than a bush 
and smaller than 
an ordinary tree. 
Coffee is one of the 
most important 
agricultural prod¬ 
ucts of Brazil, 
Mexico, Central America, the Hawaiian Islands, 
Java, Arabia, and other tropical parts of the 
world. 

What are some of the principal varieties of 
coffee? The different varieties of coffee are 
given the name of the country in which they are 
raised, or the name of the town or port from 
which they are shipped. Sometimes coffee is 
sold under a special name given by the dealer. 
Most of the coffee used in the United States 
is grown in Brazil in South America, and is 
shipped to the United States from the two 
great ports, Rio de Janeiro and Santos. The 
coffee shipped from Rio de Janeiro is called 
Rio, and that shipped from the Santos harbor 



LEVERAGES 


243 

is called Santos coffee. The most celebrated 
coffees on the market are those produced in 
Arabia, and known to the trade chiefly as 
Mocha. In the Dutch East Indies a very fine 
grade of coffee is also produced, which is in¬ 
correctly known as Java. The island of Java 
itself does not produce a high-grade coffee, but 
it has given its name to the coffees produced 
in the Dutch East Indies. A high-grade coffee 
is also grown in small quantities in Mexico, 
Porto Rico, and the Hawaiian Islands. But 
these varieties, though of excellent quality, are 
not important as to quantity. 

What are the various grades of coffee? Coffees 
are divided into nine grades, numbered from 
one to eight, while the lowest grade is known as 
“no grade.” The classification of coffees is 
determined chiefly by the number of imperfect 
grains. Grade No. 1 is supposed to have practi¬ 
cally no imperfect grains. In Grade No. 2 a 
few grains are imperfect, in Grade No. 3 a few 
more than in No. 2, and so on in increasing 
numbers up to Grade No. 8. 

Why is coffee roasted? Coffee grains that have 
not been roasted are so extremely tough that 
it is difficult to grind them. Besides, coffee 
made from them in that condition would not 
be pleasing to the taste. The roasting of the 
grain develops its aromatic properties and makes 


244 


HEALTH READER 


it brittle, easy to grind, and suitable for making 
the popular beverage known as coffee. 

What are the active principles contained in 
coffee? The aroma and flavor of coffee are 
due to certain oils developed by the roasting. 
The coffee berry also contains a considerable 
quantity of sugar, most of which is converted 
into caramel, or burnt sugar, during the process 
of roasting. It is chiefly this burnt sugar 
which gives the color and part of the taste 
to the beverage made from the coffee berry. 

But the most active principle in coffee does 
not have any noticeable taste or odor. This 
is the element, however, that produces the 
exhilaration, animation or liveliness, that is 
felt after drinking coffee. This substance is 
called caffeine. It is the same as a substance 
called theine in tea. Caffeine and theine belong 
to that class of substances known as alkaloids , 
other common types of which are quinine, mor¬ 
phine, cocaine, and nicotine. Alkaloids as a rule 
are poisonous. Caffeine is not a poison, as that 
term is generally understood, but it is a sub¬ 
stance which may produce serious injury when 
taken constantly or in too large quantities. 

There is also a considerable quantity of 
tannin in coffee. Tannin adds something to 
the taste of coffee but little or nothing to its 
wholesomeness. 


BEVERAGES 


245 


What is the effect of caffeine upon health? 

Grown persons who are strong, vigorous, and 
well nourished are able to drink coffee in moder¬ 
ate quantities without any apparent harm. 
With children the case is quite different. No 
child can possibly drink coffee, even in the 
smallest quantities, without being harmed. It 
is a beverage, therefore, which should never be 
included in the diet of children. In fact, no one 
should drink coffee before the age of at least 
eighteen years, if ever. It would be still better 
if the habit were never formed. 

Coffee acts especially as a stimulant. If we 
feel tired because of physical or mental exer¬ 
tion, that is nature’s signal that we should rest. 
If instead of resting a tired person drinks a 
cup of strong coffee, the feeling of fatigue will 
disappear and he feels able to do more work. 
But such work,'we must remember, is done at 
the expense of tissues already exhausted, and 
cannot be regarded as healthful. It is far 
better to rest when we feel tired than to drive 
away signals of distress by taking any stimu¬ 
lant, even one so mild as coffee. Even grown 
persons who drink coffee should do so only 
with the greatest moderation. 

Does coffee affect all people in the same way? 
Some people are able to drink large quantities 
of coffee without apparent harm; others are 


246 


HEALTH READER 


affected by a very small quantity. Many 
grown people who drink a cup of coffee late 
at night find as a result that their sleep is dis¬ 
turbed, wakefulness often continuing throughout 
the night. Others may drink three, four, or 
even five cups of coffee during the day and 
not suffer from sleeplessness. But it is not 
advisable to take stimulants except in special 
cases when they will help to carry one over a 
certain period in which extra exertion is abso¬ 
lutely necessary. 

The person who continually works under a 
stimulus may not feel it for many years, but 
he is almost certain to break down before his 
natural time. The drinking of coffee, there¬ 
fore, cannot in most cases be regarded in any 
other light than as dangerous to health, and 
should be absolutely forbidden to children. 

What can be said of the practice of tea drinking ? 
There is much difference of opinion among 
experts who have studied the question as to 
which is more harmful, tea or coffee. In a 
question of this kind it is well to give both sides 
the benefit of the doubt. 

We are now speaking in the interest of the 
child especially. Grown people undoubtedly 
have the right to use tea and coffee as they see 
fit, but even they should use them temperately. 
The use of tea and coffee tends to establish a habit . 


BEVERAGES 


247 


Some people begin their day by drinking one, 
two, or more cups of strong tea or coffee. If 
for any reason 
they are de¬ 
prived of this 
stimulant they 
are miserable 
the rest of the 
morning. Very 
soon they have 
a headache and 
do not feel 
inclined to 
do anything 
but find fault. . A branch of the tea plant 
Whenever you eat or drink anything which 
has practically no food value, and you are made 
unhappy when forced to do without it, you 
may be sure that you have formed a habit and 
one that is injurious. Recently a census was 
taken among the school children of a large city 
to discover how many of them drank tea or 
coffee for breakfast. It was found that about 
half of the children did drink either tea or coffee. 
Thus the fear that tea and coffee are becoming 
a real danger to the children of the country 
is not an idle one, if we accept the statement 
that one half of the children in school are form¬ 
ing the tea and coffee drinking habit. 



248 


HEALTH READER 


A short time ago the health officers of the 
city of Washington issued a circular to the 
parents whose children attended the public 
schools urging them not to allow their children 
to drink tea or coffee. The circular stated that 
children who were in the habit of drinking tea 
and coffee were restless, more or less disobedient, 
negligent of their studies, and were physically 
unfit to do good work in school. Practically 
all competent authorities on diet agree that 
children should not drink tea or coffee at any 
time. 

What is the active principle contained in tea? 

The active principle in tea is known as theine> 
a substance that is exactly the same as caffeine. 
Caffeine is the proper scientific term for both. 
Tea, like coffee, also contains large quantities of 
tannin. This substance acts on the pores of 
the membranes lining the inside of the intestines, 
tending to contract them and stop them up. 
This is easily proved by placing a little tannin 
in the mouth- The mouth at once feels, as 
we say, puckered. Any one who has eaten a 
persimmon that was not ripe understands this 
sensation or feeling. The unripe persimmon con¬ 
tains large quantities of tannin, which produces 
the effect described. Considerable quantities 
of tannin introduced into a child’s stomach 
in tea and coffee tend to hinder digestion, 


BEVERAGES 


249 


produce constipation, and so injure his health. 
It is true that most of the vegetable foods we 
eat contain more or less tannin, and that it is 
not possible to exclude it entirely from the 
diet. But we should not take any more of it 
than we have to, and above all it is not neces¬ 
sary to take it in such beverages as tea and 
coffee, which are stimulants and not foods in 
any sense of the word. 

Where does tea grow? The tea plant grows 
only in semi-tropical regions. China and Japan 
are great tea-producing countries. Tea can be 
grown in other sections of the southern part of 
the United States. But it is not cultivated to 
any extent in this country except near Charles¬ 
ton, South Carolina. 

What part of the tea plant is used in making the 
beverage? Tea is made of the dried leaf of the 
tea plant. This leaf is gathered by hand and 
dried. It is then rolled, a process often per¬ 
formed by hand. So you see a good deal of 
hand labor is required in harvesting and prepar¬ 
ing the tea leaves for market. For this reason 
the cultivation of tea can be made to pay only 
in those countries where labor is very cheap. 
The laborers on tea plantations are paid only a 
few cents a day. The principal reason why tea 
is not grown in the United States is that no 
laborers can be secured for such small wages. 


9 


25 ° 


HEALTH READER 


As yet no machine has been invented that 
will pick the perfect tea leaves and reject those 



Picking tea in a Japanese tea orchard 


that are unfit for use. It is exactly like picking 
cotton, which can be done successfully only by 
hand because the cotton bolls do not all ripen 
at the same time. Each cotton field must be 










BEVERAGES 


251 


gone over two or three times during the season 
in order to gather a full harvest. The same is 
true of the tea plant. .The leaves cannot all 
be harvested at one time because they do not 
all reach their full growth at the same time. 

What countries drink the most tea? The great 
tea-drinking countries of the world are England 
and Russia. In these countries all who can 
afford to do so drink tea. The United States, 
Australia, and Canada also use a great deal of 
tea. In the United States, although tea is used 
extensively, it is by no means so universal a 
beverage as coffee. The amount of tea used 
annually in the United States is about one 
pound for each inhabitant; the amount of coffee 
used is ten pounds for each inhabitant. 

In business offices and banks in Russia every¬ 
body is engaged at certain hours of the day in 
drinking tea, and the transaction of business 
must wait until they have finished. Tea is 
served in the banks about ten o’clock in the 
morning and at three o’clock in the afternoon. 
Then for ten or fifteen minutes everybody quits 
business and drinks tea. In England tea is 
not so commonly served in business places as 
in Russia, but it is served in that country in 
restaurants and private houses from four to five 
o’clock in the afternoon, as well as at meals. 

The wide use of large quantities of coffee and 


252 


HEALTH READER 


tea cannot be regarded as harmless. Extreme 
temperance in the use of these beverages 
must always be observed if health is to be 
maintained. As we have already said, so far 
as children are concerned, the drinking of tea 
and coffee should be entirely forbidden. 

What is.cocoa? Cocoa is a beverage prepared 
from the nuts of the cacao tree, and is very 
highly prized throughout the world. The cacao 
tree grows only in tropical regions, and for that 
reason all the cocoa used in this country must 
be imported. The nut of the cacao tree con¬ 
tains an alkaloid similar to that in tea and 
coffee, namely, theobromine. This name is de¬ 
rived from Greek words meaning “food for the 

gods.” Cocoa 
also contains 
small quan¬ 
tities of caf¬ 
feine. Theo¬ 
bromine and 
caffeine are 
closely related 
to each other 
chemically and 
have a similar 
effect on the 
nerves. Both 

A cacao branch and nut are StimulantS. 






BEVERAGES 


253 


Theobromine, however, is much less stimulating 
than caffeine, and for that reason is regarded 
as much less dangerous to health. 

There is a considerable amount of nourish¬ 
ment, especially oil, in cocoa. Cocoa has there¬ 
fore a food value. But while cocoa is less objec¬ 
tionable than tea or coffee, it is not a good 
thing for children to drink. They do not need 
anything of this kind. Milk and water are the 
only beverages that should be given a child. 

Cocoa is made by grinding the whole nut, 
with about half its oil extracted, to a fine pow¬ 
der, to which a certain quantity of either milk 
or water is added to make a suitable drink. 
It is used much less extensively in this country 
than either tea or coffee, though many prefer it to 
either of those drinks. While it is much milder 
than tea or coffee in its effect, the use of cocoa 
should nevertheless be guided by temperance. 

What is chocolate? Chocolate is cocoa in a 
slightly different form. The only difference 
between them is that in the manufacture of 
chocolate no part of the oil of the nut is ex¬ 
tracted as in the manufacture of cocoa. Hence 
chocolate is much more nutritious than cocoa, 
because of the greater amount of fat it contains. 
It is also less stimulating than cocoa, since it 
contains more oil or fat and consequently a 
smaller proportion of theobromine and caffeine. 




HEALTH READER 

Is chocolate used in other ways than as a 
beverage? When mixed with sugar, chocolate 
is extremely agreeable to the taste. For this 
reason a very large amount of chocolate is used 
in the manufacture of confectionery. Choco¬ 
late is also mixed with milk and with sugar, 
to make the well-known milk chocolate. For 
persons engaged in hard labor these sweetened 
chocolates are excellent foods. But they are not 
suitable for children to eat. They unbalance 
the ration and give a stimulant which the child 
does not need. They also give the child a taste 
for sweets which, if indulged, must necessarily 
interfere with his health and general welfare. 

What are the principal varieties of soft drinks? 
Soft drinks consist of two general classes, those 
that contain sugar, bitter extracts, spices, and 
so on, and those that in addition to these things 
contain an alkaloid. There is another class 
commonly known as “root beers.” Root beers 
are supposed to be made of extracts from aro¬ 
matic or medicinal roots, to which is added sugar 
and also a yeast which produces a slight degree 
of fermentation. They contain little or no 
alcohol. There is another large class of soft 
drinks known as “pop.” 

The soft drinks to which alkaloids have been 
added consist almost entirely of those which 
contain caffeine. Caffeine, as you have already 


BEVERAGES 


255 


learned, is the active principle in tea and coffee. 
In tea and coffee the caffeine exists, naturally in 
combination with other elements. But in soft 
drinks containing caffeine we find the pure alka¬ 
loid, usually obtained from the sweepings of the 
tea factory or from the wastes in the manu¬ 
facture of products containing caffeine. The 
pure alkaloid is more active, and for that reason 
more dangerous to health, than when combined 
with other elements as in tea and coffee. 

A few years ago soft drinks which contained 
cocaine were sold. But the war against' cocaine 
has been so vigorous that the sale of all such 
drinks practically has been stopped. 

Ginger ale is a soft drink which contains no 
alcohol and no added alkaloid. It is supposed 
to get its pungency from the use of an extract 
of ginger, but quite frequently much of its 
pungency results from the use of extract of 
Capsicum or pepper. 

What is the effect of soft drinks on the health 
of the child? Children should never be given 
soft drinks that contain any alkaloid, .such as 
cocaine or caffeine. Therefore, no one should 
be permitted to sell children soft drinks con¬ 
taining these harmful drugs. 

Another objection to soft drinks is that as 
a rule they contain large quantities of sugar. 
The child does not need any more sugar than 


HEALTH READER 


256 

he gets naturally in such food as milk and fruits. 
Neither should such extracts as spices, ginger, 
and Capsicum have a place in the child’s diet. 
All the sugar and condiments necessary to his 
welfare are supplied in the simple, wholesome 
food every child should eat. 

What are alcoholic drinks? Beverages which 
contain alcohol in any quantity or form are 
known as alcoholic drinks. These drinks are 
divided -into two great classes, fermented bev¬ 
erages and distilled beverages. 

What are the chief fermented beverages? The 
chief fermented beverages are wine, beer, and 
hard cider. Wine, for instance, is made from 
the juice of ripe grapes that has been allowed 
to ferment. 

What causes the fermentation? The fermenta¬ 
tion of grape juice and other liquids containing 
sugar is caused by the presence of a vegetable 
organism which we call yeast. There are many 
different kinds of yeast, producing different 
flavors, but all of them have this property in 
common — they can convert sugar into alcohol 
and carbon dioxide. Grape juice contains from 
fourteen to twenty-six per cent of sugar. When 
the sugar in grape juice is fermented, the quan¬ 
tity of alcohol produced is about one half the 
total quantity of sugar. Thus grape juice con¬ 
taining fourteen per cent of sugar would make 


BEVERAGES 


257 



A vineyard in the foothills 


a wine containing approximately seven per cent 
of alcohol. The juice of apples contains from 
eight to sixteen per cent of sugar. If fermented 
it would make cider containing from four to 
eight per cent of alcohol. The fermented cider 
is called “hard cider.” Grape juice and apple 
juice do not need the addition of any ferment¬ 
ing agent since yeast naturally is present in 
them. 

What is beer? Beer is a fermented beverage 
made from what is called a mash, that is, a 
quantity of cereals and hops crushed and heated 
in water. Barley is the chief cereal used in 











HEALTH READER 


258 

making beer. Beer made in the United States 
contains from less than two per cent to a little 
more than four per cent of alcohol. 

What is ale? Ale is the same as beer except 
that it is made of a heavier mash and contains 
from five to eight per cent of alcohol. Because 
of the higher percentage of alcohol, ale is much 
more injurious than beer. 

What is champagne? Champagne is a wine 
which is fermented in sealed bottles. It is 
made in a certain department or division of 
France only. Wine fermented in the bottle 
in other localities is known as sparkling wine. 
When the bottles containing champagne or 
sparkling wines are opened, gas escapes from 
the liquid, forming small bubbles which for a 
long time continue to rise to the surface. 

What relation have these fermented beverages to 
health? For the growing child, the use of fer¬ 
mented beverages, even in small quantities, is 
very injurious to health. Alcohol is a habit¬ 
forming drug, and when once you begin to use 
it you are apt to like it a little better each day, 
and thus be inclined to take more and more of 
it. For this reason alcohol is a dangerous drink. 

What is grape juice ? Grape juice is a beverage 
made from the unfermented juice of grapes. 
The juice is heated so as to kill all the yeasts or 
fermenting substances in it, and is then set aside 


BEVERAGES 


259 


to allow the solid matters to settle. After a few 
days, when the grape juice is bright and clear, 
it is put into bottles, sealed air-tight, and 
subjected for a certain length of time to a 
temperature under the boiling point of water. 
Juices put up in this way remain bright and 
clear, and will keep almost indefinitely until 
the bottle is opened. 

Grape juice is not only a pleasant drink but 
also has food properties, due chiefly to the 
sugars it contains. It also has acid properties, 
due chiefly to the tartaric acid contained in it. 
These acid properties are thought to be favor¬ 
able to health, not alone because of the acid, 
but because of the potash with which the acid 
is combined. Well-made and well-preserved 
grape juice is palatable and wholesome, and 
may be used occasionally by children, but only 
in small quantities. 

What are distilled liquors? The principal dis¬ 
tilled beverages are whisky, brandy, rum, and 
gin. Whisky is made from fermented cereals 
in the same way that beer is made, except that 
no hops are added. After the cereals are fully 
fermented the mash is put into a large copper 
vessel and distilled. The raw whisky produced 
by this process of distillation is then placed in 
oak barrels and stored for a number of years. 

Brandy is made by distilling wine. It is 


260 


HEALTH READER 


therefore an alcoholic product of the grape. 
Rum is a product distilled from fermented 



A small still for the distillation of liquors 


molasses, just as whisky is distilled from fer¬ 
mented cereals. Gin is distilled alcohol of any 
kind flavored with such substances as juniper 
and sloe berries. 

To make the vast array of alcoholic products 
known as liquors, cordials, cocktails, and so 
on, alcohol is mixed with sugar and other sub¬ 
stances, principally flavors and colors. All such 
mixtures are very injurious. Some alcoholic 
products, like absinthe, contain substances so 
poisonous in nature that they produce the 
most dreadful effects. 

Those who use alcoholic beverages are less 
efficient in their work, have less resistance to 






























BEVERAGES 


261 


cold, and become fatigued more easily than 
those who do not use them. They are far 
more likely to have a diseased liver, or tuber¬ 
culosis and pneumonia. They are often shut 
out from useful employment, since many in¬ 
dustries will not accept them. The Pennsyl¬ 
vania railroad will not employ - any one who 
uses alcohol. Neither does it allow alcoholic 
beverages to be sold on its dining cars. Why 
should a boy form a habit which will handicap 
him in earning a living and shorten his life 
as well? 


QUESTIONS TO HELP THE PUPIL 

1. What are the only beverages a child should drink? 
2. What does water dissolve as it passes through the 
soil? 3. What mineral substance is most commonly 
found in well water? 4. What is the difference between 
“hard” and “soft” water? 5. How can hard water be 
softened? 6. When do we need a greater quantity of 
water and when a smaller? 7. Why is it better not to 
drink water while eating? 8. Is sour milk wholesome? 
9. Why is coffee roasted? 10. What is the most active 
principle in coffee? in tea? 11. What is the name given 
to this class of substances? 12. How do alkaloids affect 
people? 13. What is the effect of tannin? 14. In what 
countries is tea drinking very common? 15. What 
stimulant is found in cocoa? what other substances? 
16. Is cocoa good for children? 17. What is the differ¬ 
ence between chocolate and cocoa? 18. For what is 
chocolate used extensively? 19. Should chocolate be 
eaten by children? 20. What are soft drinks? 21. 
What is the danger of soft drinks? 22. Name some 
alcoholic drinks. 23. What causes fermentation ? 24. Is 

the use of fermented or distilled beverages injurious? 


XXIV. Tobacco and Its Dangers 

What is tobacco? The tobacco plant, from 
which various kinds of tobacco are made, grows 
extensively in the southern states of the Union, 
especially in Florida, North Carolina, Virginia, 
and Kentucky. The tobacco plant is also cul¬ 
tivated in Connecticut, Ohio, Indiana, and the 
southern portion of Wisconsin. The broad 
leaves of the plant, after the stems have been 
removed, are manufactured into smoking to¬ 
bacco, chewing tobacco, and snuff. 

What is the danger of tobacco? We have 
read in the preceding chapter of the dangers of 
drinking coffee, tea, and cocoa, because of the 
alkaloids they contain. Equally dangerous, if 
not more so, and for the same reason, is the use 
of tobacco. Tobacco contains an alkaloid called 
nicotine. In its pure state nicotine in small 
quantities will cause death. But in tobacco, 
as in coffee and tea, the alkaloid exists in such 
minute quantities that the process of poisoning 
goes on very gradually and the tobacco user 
does not feel the effects until the habit is firmly 
fixed and Very hard to overcome. 

The use of tobacco in any form is extremely 
injurious to the heart, the lungs, the digestive 


262 


TOBACCO AND ITS DANGERS 


263 


organs, and the nerves. The heart fails to do 
its work as it should. Its action becomes 
irregular and at times it misses a beat. When 
the heart fails to supply the organs of the body 
with the blood they need they cannot do their 
work properly and so the stomach, the liver, 
the kidneys, the nerves—all the organs—are 
hindered in their functions. 

Cigarette smoking is particularly harmful. 
Instead of the pure air that the body needs, a 
poisonous nicotine-filled smoke is drawn into 
the lungs. There the nicotine passes into the 
blood and is carried through the entire system. 
The heart fails to do its work properly. Diges¬ 
tion is hindered. The phagocytes or cell eaters 
in the blood are weakened so they cannot guard 
the body against germs and bacteria, and, 
sooner or later, the cigarette smoker falls an 
easy victim to disease. 

Not only is the physical health of the tobacco 
user ruined by the slow poison. The mind of 
the habitual cigarette smoker is so affected that 
he cannot concentrate, his memory is poor, and 
he cannot compare in general scholarship with 
those who do not use tobacco. These facts 
have been proved by actual tests carried out in 
a number of schools. It has also been proved 
that those who use tobacco are stunted in 
growth. Also their muscles are weakened and 


264 


HEALTH READER 


so they cannot hope to excel in athletic sports 
of any kind. 

Does it not seem foolish for any one deliber¬ 
ately to use tobacco when he knows that sooner 
or later it will so injure him in body and mind 
that he can no longer enjoy life or hope to suc¬ 
ceed in anything he undertakes? 

QUESTIONS TO HELP THE PUPIL 

1. Where in the United States is the most tobacco 
raised? 2. What part of the plant is used in manufac¬ 
turing tobacco ? 3. What is the similarity between coffee 

and tea, and tobacco? 4. What alkaloid is contained in 
tobacco? 5. What is the effect on the body of nicotine 
in the pure state? 6. Why does not the tobacco user 
feel the effects of the nicotine immediately? 7. What 
is the effect of nicotine on the heart? 8. Why does the 
cigarette smoker fall an easy victim to disease ? 9. What 
is the effect of cigarette smoking on the mind? 10. Can 
the cigarette smoker hope to succeed in what he under¬ 
takes? 11. Is the use of tobacco a foolish habit? why? 


XXV. Confections, Sirups, and Pastry 

What are candies ? Candies are products 
made chiefly of sugar, with the addition of 
coloring and flavoring matters, and put up in 
various shapes and forms attractive to the eye. 
The terms “candies” and “confections” *do 
not mean quite the same thing, although a 
candy is always a confection and a confection 
may be a candy. Confections are products 
which may contain fruit in addition to the 
elements that are used in making candies. A 
jam or jelly is a confection, but not a candy. 

From what plants is sugar produced? The 
sugar we buy in the grocery store is made 
chiefly from two plants, the sugar cane and 
the sugar beet. Small quantities of sugar 
made from the maple tree may be found on the 
market, and in some parts of the world sugar 
is produced from other plants, for instance the 
sugar palm. At least four fifths, and possibly 
a larger proportion, of the sugar used in the 
United States is made from sugar cane. 

Sugar cane grows luxuriantly in rich soil that 
has been properly tilled. It looks like corn 
and sorghum. It has a jointed stalk, and 
often grows to a great height, bearing blades 
at each joint. As it ripens, the sugar cane 
265 


266 


HEALTH READER 


becomes so heavy that it hardly ever stands up 
straight. It falls over, especially during a heavy 
wind, becoming a tangled mass that seemingly 
would make the harvester’s task almost hopeless. 

Sugar cane grows in a number of the southern 
states in our country, Louisiana leading in its 
production. In some seasons over three hun¬ 
dred thousand tons of cane sugar are made 
in Louisiana. Cuba, however, makes more 
cane sugar than any other country in the world. 
Its annual output of cane sugar is now about 
three million tons. Over five hundred thousand 
tons are made in the Hawaiian Islands. Porto 
Rico and the Philippine Islands also produce 
a large quantity of cane sugar. But Cuba is 
the principal source of that which is imported 
into this country. 

Sugar beets grow in more northern latitudes. 
In this country the great beet-growing states 
are Michigan, Colorado, and California. The 
beet often contains from fourteen to eighteen 
per cent of sugar. It is thus richer in sugar 
than the sugar cane raised in this country, which 
usually contains only from eleven to thirteen 
per cent. But the sugar cane of Cuba and that 
of the Hawaiian Islands is often richer in sugar 
than are beets. 

What ingredients are mixed with sugar in making 

candies? Usually some coloring material is 


CONFECTIONS , SIRUPS , PASTRY 267 

mixed with the sugar. These coloring matters 
are either coal-tar or vegetable dyes. Various 



Pulling homemade taffy 


flavoring matters, such as cinnamon, pepper¬ 
mint, chocolate, almond, coconut, and other 
substances are used also to give each kind of 
candy a particular flavor. It requires great 
skill and long practice to make attractive 
candies. 

Can we make candy at home ? One of the most 
enjoyable pastimes on a cold winter evening 
is the making of so-called “taffy.” The ordi¬ 
nary sirup is not suitable for making high-grade 
taffy. You must first get a genuine sugar-cane 
sirup or good New Orleans molasses if you wish 
























268 


HEALTH READER 


to make a good first-class taffy. Then you 
must boil the molasses or sirup, stirring care¬ 
fully so as not to let it scorch, until a spoonful 
dropped into cold water makes a waxy, hard 
mass. After that the boiling sirup is poured 
into greased plates and set in a cool place until 
it begins to harden. It is then taken out and 
pulled vigorously. During this process it takes 
in a large number of small air particles and 
changes in color to yellow or, when the sirup 
Is very pure, almost to white. Such taffy is 
delicious from the candy eater’s point of view. 
It is not so easy to make fancy candy at home, 
but candies like fudge are easily made there. 

Are injurious substances used in making candy? 
Unfortunately, yes. Within the last few years 
some candies have been coated with a soluble 
gum in order to give them a certain gloss or 
finish. This coating has sometimes been found 
to contain arsenic, which is dangerous to the 
health of the consumer. The coal-tar dyes 
also that were formerly used were more or less 
poisonous. Fortunately, the food laws have 
practically succeeded in stopping the use of 
such materials. To-day a number of manu¬ 
facturers use only pure vegetable substances 
in making candies. Moreover, their candies, 
which are highly attractive in color and glazing, 
contain no poisonous substances and are so 


CONFECTIONS , SIRUPS , , 47 VD PASTRY 269 


made that from the standpoint of purity they 
are perfectly safe. 

Candies are also made to a considerable extent 
of glucose. 

What is glucose? Glucose is a thick, sirupy, 
almost colorless product derived from the 
starch of Indian corn or of the potato by treating 
it with an acid at a high temperature. Most 
authorities regard glucose as harmless. How¬ 
ever, since glucose is an unnatural sugar, that 
is, a sugar not made in the natural way, it may 
not be so wholesome as a natural sugar. It 
is a well-known fact that very young animals, 
such as mice and chickens, fed with glucose 
instead of ordinary sugar, do not thrive. This 
is true also of bees. So it appears that if chil¬ 
dren are to eat candy at all—and it is best for 
them not to do so—those candies will do least 
harm which contain no glucose. 

What effect has the eating of candy on the health 
of the child? The ingredients themselves that 
are used in making candy may be regarded as 
harmless. That is, there is in them no special 
danger. Sugar, chocolate, spices such as cin¬ 
namon and peppermint, honey, butter, and such 
substances cannot be regarded as harmful. 
Aside from the nature of the ingredients it 
contains, it cannot be too strongly emphasized 
that candy is not a suitable food for children. 


270 


HEALTH READER 


It contains practically no material which will 
build or restore tissue, but consists essentially 
of sugar, which produces only fat, heat, and 
energy. Hence children who eat large quan¬ 
tities of candy unbalance their ration because 
they have no appetite for proper food. As a 
consequence the bones and teeth are not well 
nourished, the muscular tissues of the body 
suffer from hunger, and the work that food in 
general is supposed to do is not done. Unfor¬ 
tunately, candy is eaten chiefly between meals 
and that is an additional danger to health. 

If older children engaged in active exercise 
and hard work wish to eat candy, they can get 
a good deal of strength and energy out of it, 
and it will thus be of use to them. But as a 
food for young children candy must always be 
considered dangerous. 

Grown people who are active and get much 
physical exercise may eat well-made candy in 
moderation without injury. 

What is the effect of candy upon the teeth? It is 
generally admitted by everybody that children 
who eat a great deal of candy have poor teeth. 
The real danger to good health in eating candy 
is that the child is deprived of those elements 
which are needed for building bone and teeth. 
If there is not enough of these elements in the 
blood, nature robs the teeth to strengthen the 


CONFECTIONS , SIRUPS , PASTRY 271 

bones, and thus in early childhood the teeth 
are poor. Even the first set of teeth may be 
soft and prone to decay, 
and such premature de¬ 
cay threatens not only 
the tooth attacked but 
the permanent tooth that 
is to come after. Hence 
during the teething pe¬ 
riod, which lasts up to 
the age of ten or twelve, 
the child should not be 
given sweets—that is, 
candy—in any quantity. 

If the child never acquires 
a “sweet tooth/’ as it is 
called, he will not cry for sweets. He will be 
content to eat the foods in which nature has 
provided for him all the sugar he needs. 
Candy, therefore, in any form or shape, is in¬ 
jurious to the teeth and should never be given 
to young or growing children. 

What is meant by the word “sirup”? The term 
“sirup” properly applied means a product con¬ 
sisting chiefly of sugar and made by the evapo¬ 
ration of the sap or juice of a sugar-producing 
plant until it becomes a thick and somewhat 
sticky fluid. The sirups most commonly in 
use in the United States are made from the 



A bad set of teeth. “Not 
healthful nor pretty ” 


272 


HEALTH READER 


sap of the maple tree, sorghum, or sugar cane. 
These products are called maple sirup, sorghum 
sirup, and cane sirup. The sap of the sugar 
beet, although it carries a large quantity of 
sugar, does not make a good-tasting sirup 
because of the large quantity of mineral salts, 
mostly potash, soda and lime, contained in it. 
When this sap is evaporated until it forms a 
thick sirup it tastes bitter or salty and is not 
commonly used for food. 

Are sirups always made in the ways described? 
Unfortunately, most of the sirups on the market 
in our country are not made like the pure 
products described above. 

In making manufactured sirups, small quan¬ 
tities of these excellent products, maple sirup, 
sorghum sirup, and cane sirup, are used simply 
to flavor large quantities of glucose. 

How is glucose used in sirup? We have 
already learned how glucose is used in the 
manufacture of some kinds of candy. Glucose 
is faintly sweet, but is otherwise flavorless, and 
is not pleasing enough to the taste to be eaten 
alone. When mixed with one of the sirups 
mentioned it acquires the character and flavor 
of the particular sirup to which it is added. 
It thins the sirup, increases its bulk, lightens 
its color, and makes an attractive product 
which is used extensively throughout the 


CONFECTIONS, SIRUPS, AND PASTRY 273 


country. Melted brown sugar is also used as a 
sirup. It is often mixed with glucose, or with 
some of the genuine sirups that have already 
been mentioned. 

The containers in which these glucose sirups 
are sold are not always correctly labeled, and 
when you go to the grocery store and simply 
ask for a sirup, the chances are you will get 
neither maple, sorghum, nor cane sirup, but 
such a mixture as we have described. 

What is the food value of a sirup ? A pure sirup 
or a manufactured sirup depends for its chief 
food value on the sugar or sugars which it 
contains. All sugars have practically the same 
food value. They are burned in the body 
completely when it is in a state of health, and 
furnish heat and energy. 

Do sirups have any other value ? The pure sirups 
contain mineral substances which are also useful 
to the body. All natural sirups — maple, sor¬ 
ghum, and cane — contain from two to three 
per cent of mineral substances, which are 
valuable aids to digestion and promote health. 
These substances, such as lime, phosphorus, 
soda, and potash, are useful in building bone 
and teeth and other tissues of the body and 
in producing the alkaline element in the blood 
which is needed to help the heart and other 
organs do their work. So it is plainly to be 


274 


HEALTH READER 


seen that if one desires to eat sugar it is best 
in the form of natural sirups, because of the 
mineral nutrition which they give, t Candies 
made from these sirups are to be preferred to all 
others. Even children might be permitted the 
moderate use of candies made from pure maple, 
sorghum, or cane sirup, provided the habit of 
eating sweets does not become so strong that 
they crave larger quantities than are good for 
them. 

How does sirup affect the health? Natural 
sirups are wholesome when not eaten in too 
great quantities. When any one engages in 
active play or manual labor these sirups may be 
eaten without fear of injurious results. But 
if these sirups are eaten alone they unbalance 
the ration; that, is they provide too much sugar 
properly to nourish the body. Sirups may 
therefore be eaten with advantage with cakes 
made out of cereals rich in protein, and especially 
if butter is also used on the cakes. We then 
have a more or less well balanced ration. The 
butter furnishes the fat, the cereals furnish the 
starch, the protein, and a part of the mineral 
matter, and the sirup furnishes the sugar and 
also a considerable quantity of mineral matter. 

The sirups made out of glucose contain almost 
no mineral matter except common salt. Salt is 
a wholesome and necessary ingredient of our 


CONFECTIONS, SIRUPS, AND PASTRY 275 

food, and hence is not objectionable in the 
quantities in which it is present in glucose* 
Nevertheless we can get plenty of salt from 
other kinds of foods, and it should not be neces¬ 
sary to eat glucose in order to get it. 

What is honey? All plants produce more or 
less sugar during their growth. Some are known 
particularly as sugar-producing plants because 
of the large quantity of sugar they contain. 
Among these are the maple tree, the sugar palm, 
sorghum, sugar cane, and many varieties of 
beets and other garden vegetables, such as 
sweet corn, melons, fruits, and grapes. 

At the time of flowering almost all plants give 
out a large quantity of sugar in connection with 
the bloom. The sugar, or nectar as it is called, 
attracts the visits of bees and other insects 
that gather honey for food. 

The honey we eat is gathered by an insect 
known as the honey bee. Many thousands of 
these bees live in one family or colony. Dur¬ 
ing the flowering season they go long distances 
and bring back little stores of sugar for the 
common storehouse of the family. They build 
little five-sided houses or rooms, usually in 
hollow trees or in hives, and fill them with this 
honey after it has passed through their bodies. 
The bees also secrete a peculiar form of acid, 
called formic acid from the Latin word for 


276 


HEALTH READER 


ant. A little of this acid is imparted to the 
honey, and helps to give it its peculiar and 
distinctive flavor. 

There are very few people who do not like 
honey. It is used exactly as sirup is used, by 
spreading it on bread or cakes or in making 
sweet cakes. Bee keeping is carried on in all 
parts of the country. Large quantities of honey 
are produced, especially in California, where 
the bees gather their honey largely from the 
wild sage of th£ deserts and from the flowers 
of the many fruit trees. 



A colony of bees 


What is the food value of honey? As a food, 
honey depends for its value on the sugar it 
contains. Therefore it unbalances the ration 






CONFECTIONS , SIRUPS , AiVD PASTRY 277 

and should be eaten in moderation, especially 
by children. Honey contains very little min¬ 
eral matter, the sugar gath¬ 
ered by bees being remark¬ 
ably pure. So honey is 
not so well adapted to pro¬ 
mote the growth of the body 
as the natural sirups. But 
for grown persons who do 
hard work honey is an ex- A co ™ b °f ho ™y 
cellent food, as it furnishes a large amount of 
heat and energy. 

Does the eating of honey affect the health? 

Pure honey, eaten in small quantities, cannot 
be regarded as harmful or injurious to health. 
But sometimes the bees gather poisonous sub¬ 
stances, or introduce poisonous matter into 
honey, and there are cases on record of severe 
poisoning due to the eating of it. For this 
reason it is always advisable to eat honey 
temperately, for even good honey if eaten in 
too large quantities may cause severe illness. 

The taste of honey is so attractive that it is 
difficult to control the appetite for it. For this 
reason, when children eat honey the quantity 
they are allowed to have should be measured 
out by their parents and no more should be 
given, even if the children cry for it. Otherwise 
the results from eating honey may be serious. 








278 


HEALTH READER 


What is pastry? The term “pastry” is the 
name given to such foods as pies, patties, and 
tarts. First a holder or container is made from 
a dough of wheat flour to which a large amount 
of fat, or shortening, has been added. This 
holder or container is then filled with fruits, 
meats, or other materials, and baked. 

Pastry is served at the end of the meal, as 
dessert. Usually when we come to pastry we 
have already had enough to satisfy our hunger. 
So the pastry we eat is only an added burden 
to digestion, which is really the chief objection 
to its use. But, if we stop eating while still 
a little hungry, and then have the pastry, there 
is no great objection to a moderate use of such 
food. This is especially true of fruit pies. 

In England by the term “pie” is usually 
meant only pastry in which the filling consists 
of meat. In this country the term “pie” is 
used no matter what the filling may be. In 
fact, most of our pies are made with vegetable, 
fruit, or custard filling, a very small proportion 
only being made with meat filling. Even 
mince pie, which is supposed to contain meat, 
generally contains very little of it, especially if 
not made at home. The filling is principally 
made up of fruits, raisins, sugar, and spices. 

The fillings used in pies made in this country 
are chiefly apple, peach, cherry, blackberry, 


CONFECTIONS , SIRUPS , AA/X> PASTRY 279 


raspberry, pumpkin, custard, lemon, and mince¬ 
meat. Strawberries and some other fruits are 



Homemade pastry. Making pies 


often served in a kind of pie known as short¬ 
cake, in which the crust and the fruit are placed 
in successive layers. 

Are pies digestible ? Fat and flour are blended 
so closely in the piecrust as to interfere to a 
certain extent with the digestion of each. Pro¬ 
tein, which is contained in the flour, is digested 
largely in the stomach, while fat, of which the 
piecrust contains a great deal, is digested largely 
in the small intestine. The starch found in the 
flour may be digested partly in the mouth and 
partly in the small intestine. Thus, when the 
fat is thoroughly mixed with these substances 






28 o 


HEALTH READER 


as it is in piecrust, the protein and the starch 
are prevented from being acted upon by the 
digesting agents in the mouth and stomach 
which carry on the digestion of such foods. In 
the same way the particles of fat may be 
carried into the small intestine so closely inter¬ 
mingled with undigested protein or starch as to 
cause difficulty or delay in the digestion of the 
fat. So pastry, although it may be highly nutri¬ 
tious, cannot be recommended as an easily 
digested food. It should be eaten in modera¬ 
tion, and if one has already had food enough, to 
satisfy hunger when the pastry is served, then 
it should not be eaten at all. 

To avoid overeating it has been suggested 
that pastry should be served at the beginning of 
a meal. But this suggestion is hardly accept¬ 
able. The principal object of eating is to nour¬ 
ish the body. Hence, in the order of eating, 
those foods which are known to be best suited 
for the nourishment of the body should be given 
the preference. The best plan seems to be not 
to serve pastry at all, or at least to give it in 
smaller portions, especially to children. The 
growing child should eat very little of it, 
while the hard-working grown person may eat 
it more freely. 

What is ice cream? It is difficult to define a 
product that is made in so many different ways 


CONFECTIONS , SIRUPS , diVD PASTRY 281 

and out of so many different materials. But 
an ice cream that is properly called ice cream 
and is made out of the right kind of materials 
can easily be defined. Such ice cream is a 



Freezing ice cream at home 


product made by mixing with cream the proper 
amount of sugar and harmless flavoring matter 
and then freezing the mixture. 

What is the food value of ice cream? The food 
value of ice cream is high. The cream itself 
contains butterfat, milk sugar, and nitrogen 
(protein), the percentage of fat being very high. 
In standard cream the content of fat is never less 
than eighteen per cent. To this cream is added 
a certain amount of sugar, a food which furnishes 
large quantities of heat and energy. Ice cream 
contains only very little protein and mineral salt 
(potash, phosphoric acid, lime). Thus it is a 


10 






282 


HEALTH READER 


food which furnishes great quantities of fat, 
heat, and energy, and is well suited for grown 
people who take a good deal of physical exer¬ 
cise. But it is not well suited to the nourishment 
of growing children since it unbalances the 
ration. It may be eaten by children in very 
small quantities only, if injury to health is to 
be avoided. It should not be eaten at all by 
children under five years of age. 

QUESTIONS TO HELP THE PUPIL 

1. What is candy? 2. From what plant products is 
sugar chiefly manufactured? 3. What does sugar cane 
look like? 4. Where is most of the cane sugar made? 
5. Name a great beet-growing state. 6. May candy be 
made at home? 7. Are injurious substances sometimes 
used in making candy? 8. What law has succeeded in 
stopping this? 9. Is glucose a healthful substance to 
use in making candy? 10. Is a little candy harmful to 
grown people? 11. Why is candy not good for children? 
12. What effect has it on the teeth? 13. What is sirup? 
From what plants is it made? 14. What sirup is made 
from the sap of a tree? 15. Does the use of sirups un¬ 
balance the proportion of food elements necessary 
for proper nourishment? why? 16. What beneficial 
substances do pure sirups contain? 17. Why are sirups 
good for people who work hard? 18. What kind of a 
ration do we get if we eat sirup and butter with cakes 
made of cereals? 19. Are glucose sirups to be regarded 
as wholesome? 20. What is honey? 21. Where do bees 
get the sugar or nectar? 22. Why should honey be eaten 
in moderation? 23. What is pastry? 24. What is the 
chief objection to pastry? 25. Name some fillings that 
are used in pies. 26. Why is piecrust difficult to digest? 
2 7. What are the proper ingredients of ice cream ? 28. For 
what class of people is ice cream a good food? 


PART THREE 


XXVI. How Do We Grow? 


A STUDY OF FOODS 

What is the purpose of food ? All living things 
require food. This is true of plants as well as 
of animals. The young plant gets its first 
nourishment from a supply of food stored in 
the seed. Some seeds, like nuts, are very large, 
and contain a great deal of nourishment. Other 
seeds are very small and so can contain only 
a small quantity of nourishment. But all seeds 
always contain food enough for the young plant 
during the first period of growth. 

There is enough food in the 
seeds of all cereals to sustain 
the young plants growing 
from them for several days. 

But then, if no additional 
supply of nourishment is pro¬ 
vided, the young plants die. 

You may prove this by a 
simple experiment. Fill two 
basins with distilled water. 

Distilled water contains practically no food 
that will promote plant growth. Over the sur¬ 
face of the water place cloths that have been 
283 



Sprouting cereals 
in water 








284 


HEALTH READER 


thoroughly washed in distilled water to remove 
any material that might nourish the plant. 
The threads in the cloth must be far enough 
apart to leave space for young rootlets to grow 
down into the water. On top of the cloths place 
a number of grains of wheat, and set the two 
basins in a dark place where the temperature 
is not below fifty-five or sixty degrees. When 
the wheat has sprouted and is fully developed, 
bring the basins out into the light. The sprouts 
will soon turn green, and the roots will reach 
down through the cloth into the water. Grad¬ 
ually the grains of wheat will disappear, leaving 
only the hulls. Then the growth of the plant 
will cease. 

Now add a little plant food consisting of 
phosphate of soda, powdered gypsum, and 
nitrate of potash to the water in one of the 
basins. Then watch what takes place. 

In the basin where you added the plant food 
the plants will grow vigorously as long as the 
plant food lasts. The young plants in the 
other basin, where no nourishment was added, 
will die. In the first case you fed the plant; 
in the second you starved it. Corn or any 
other cereal may be used for this experiment. 

When an animal is born it can live two or 
three days without any nourishment. But 
very soon thereafter, if no food is given it, 


HOW DO WE GROWf 


285 


the young animal will die. Given the proper 
nourishment, it will not only live, but it will 
continue to grow. Thus we see that in order 
to live alid to grow both animals and plants 
must be supplied with food. 

How may the foods of animals be classified? In 
classifying foods suitable for animals, we find 
five principal divisions: Mineral foods (lime, 
phosphate, soda, potash), nitrogenous foods 
(protein), carbohydrates (sugar and starch), oils 
and fats , and condiments (seasonings). All 
the food we eat may be classified under these 
five heads. 

Foods may also be classified according to 
other standards. Most foods may be classified 
broadly as animal or vegetable products. In 
a more detailed classification of foods according 
to their natural form we have meats, poultry, 
fish, game, cereals, milk, fruits, vegetables, and 
nuts. With regard to their preparation foods 
may be classified broadly as cooked or raw foods. 
With regard to the various forms in which they 
are prepared for use they may be classified as 
flour, bread, butter, cheese, cream, cured meats, 
smoked meats, dried fruits, canned fruits, 
canned vegetables, breakfast cereals, and such 
foods as jams, jellies, and preserves. 

In our discussion of foods we shall begin with 
the minerals. 


286 


HEALTH READER 


A STUDY OF MINERAL FOODS 
What are the chief minerals contained in foods? 

Nearly all the mineral substances that are 
present in the soil are also present in vegetable 
products. Animals must have some of these 
mineral foods at all times in order to live; others 
are valuable at certain times and under certain 
conditions. The mineral substances that ani¬ 
mals must have are phosphoric acid, lime, iron, 
soda, potash, iodine, and magnesia. 

What foods contain the most iron? Some kinds of 
food contain a great deal more iron than others. 
Of the vegetables, spinach is believed to con¬ 
tain the largest amount. There is also much 
iron in the cereals, and traces of it are to be 
found in most of the foods we eat. 

Is there any danger in taking too much mineral 
substance into the body ? The rule that applies to 
all other foods when taken in excess also applies 
to mineral substances. If more minerals are 
taken into the body than are required for its 
proper nourishment and growth, the body must 
get rid of the excess. This is done by the 
organs that remove wastes from the blood and 
send them out of the body, especially the kid¬ 
neys. To get rid of an excess of minerals too 
great a burden is placed on these organs, and 
this, if continued, may prove harmful. 

As a general rule, when we eat one hundred 


HOW DO WE GROWf 


287 


pounds of food, from one and a half to two 
pounds of it should consist of mineral substances. 
More than this would probably be harmful, 
and any considerable quantity less would cer¬ 
tainly be so. Therefore, in the preparation of 
food for eating, the natural mineral content 
should be reduced as little as possible. It is 
really better to eat the skins and outer cover¬ 
ings of such foods as cereals and potatoes and 
apples, than it is to discard them, for in the 
bran of cereals and in the skins of potatoes, 
apples, and other fruits and vegetables is found 
most of the mineral content of those food 
products. 

A STUDY OF FOODS CONTAINING NITROGENOUS 
SUBSTANCES 

What foods are the chief sources of protein? 

Protein, the food element containing nitrogen, 
is present in nearly all our vegetable and animal 
foods. Among the foods containing the largest 
proportion of protein is lean meat. About sixty 
per cent of the content of ordinary fresh lean 
meat is water, the remaining forty per cent being 
largely protein and fat. This is true of both - 
red and white meats. 

Milk is another animal food in which there is 
much protein. About three and a half per cent 
consists of protein. But since there is only 


288 


HEALTH READER 


thirteen per cent of dry food in milk, the rest 
being water, it is evident that a little more 
than one fourth of the 
total amount of dry food 
in milk is protein. In 
cheese the proportion of 
protein is considerably 
greater than it is in milk. 
There is also a large quan¬ 
tity of fat in cheese. 

Another food contain¬ 
ing a large proportion of 
protein is the egg. The 
white of an egg is more 
than seventy per cent 
water. The remainder, 
or thirty per cent, consists 
largely of protein. The yolk of an egg contains 
less water than the white of the egg, and also 
much less protein. A large part of the yolk of 
the egg consists of fat. 

Among the vegetable foods, peas and beans 
are rich in protein. Among the cereals, oats 
contain the highest proportion of protein and • 
rice the lowest. Not more than eight per cent 
of the content of rice is protein. From ten to 
fifteen per cent of the content of wheat is 
protein, while Indian corn contains less protein 
than wheat, and barley and rye almost as much. 



Pea pods 


HOW DO WE GROW? 


289 


While peas and beans contain much protein, 
the amount in other vegetables is compara¬ 
tively small. 

The percentage 
of protein in 
the potato is 
small. Fruits _ 
and succulent ' 
vegetables also \ 
contain a com¬ 
paratively small 
amount of pro¬ 
tein. Nuts, and 
oily seeds such 
as cottonseed 
and flaxseed, 
contain much 
protein. From Bean pods 

this we learn that if we should limit our diet to 
a single food we might select one with a very 
high content of protein, such as oats, peas, or 
beans, or we might select one with a very low 
content, such as rice, potatoes, or fruits. But 
if we know the proportion of protein in the 
various kinds of food we can select them so 
as to get the exact amount of protein needed 
for our proper nourishment and growth. 

How much protein should we eat a day? This 
is a question that has been the subject of much 










2Q0 


HEALTH READER 


discussion. Some experts claim that we should 
eat a large quantity of protein; others claim 
that a small amount is better. The proper 
amount is probably between these two estimates, 
or a medium quantity. 

A man who weighs about one hundred fifty 
pounds and is engaged in active work needs 
from three and two tenths to four and three 
tenths* ounces of protein* a day. But we must 
remember that other food elements are as neces¬ 
sary to nutrition as protein. The proper quan¬ 
tity of those elements will be discussed later. 

Are there differences in the nutritive qualities of 
proteins? The proteins in different kinds of 
food, both animal and vegetable, differ in nutri¬ 
tive value. Comparing the body to a house 
built of brick or stone the protein may aptly 
be regarded as the bricks or stones out of which 
the structure is built. Protein is the essential 
material composing the muscular tissues of the 
body. It is also a very important element of 
the nerves and the brain, and is one of the chief 
substances in the blood. Protein is almost the 
sole material in the hair, the nails, and the skin. 
It is a very important element in the bones of 
the body. It is found, although in small quan¬ 
tities, even in the fats of the body. Thus the 
statement that protein is the principal building 
material in the bodily structure is fully justified. 


HOW DO WE GROW? 


291 


You have noticed that different clays make 
different kinds of bricks. Some are red, some 
gray, some almost white, and some yellow. 
Some bricks are very hard, some have been 



melted, or vitrified as it is called, until they are 
glassy, and some are so resistant to heat that 
they cannot be vitrified, and for that reason 
are used to line furnaces. And yet all bricks 
are made out of clay. In the same way we may 



























292 


HEALTH READER 


find differences in the protein “bricks” out of 
which the bodily structure is built. 

Among the best protein bricks with which to 
build the human body are those made from the 
casein of milk and the gluten of wheat. The 
protein of Indian corn, if no other “clay” is 
mixed with it, makes, the poorest bricks. 

The proteins themselves are not bricks or 
building stones of the body any more than beds 
of clay or unquarried rocks are bricks or building 
stones of a house. Just as bricks are molded 
and baked in the kiln, so the proteins are treated 
in the digestive apparatus and made into 
“building stones” or “bricks” suitable for the 
bodily structure. 

When proteins are used in the body, whether 
they are built into the tissues or are burned 
directly in the blood stream , a waste material 
(urea) forms which is more or less injurious 
or poisonous. For this reason not more of this 
building material than is really necessary for 
the growth and nutrition of the body should be 
used. 

The foods containing protein in large propor¬ 
tions and carbohydrates in small proportions 
or none at all are generally the most expensive. 
A nation that produces plenty of food, or has 
plenty of money with which to buy food, is apt 
to choose expensive foods, such as meats, eggs, 


HOW DO WE GROWt 


293 


and milk. Therefore the people of that nation 
are apt to eat too much protein and hot enough 
carbohydrates. On the other hand, if a nation 
produces little food, and has little money with 
which to buy food, it must content itself with 
foods that are poor in protein, such as rice, 
Indian corn, and potatoes. The people of such 
a nation no doubt do not get enough building 
material. But the nation whose resources per¬ 
mit it to take the middle course between these 
two extremes will have the advantage, since 
the people will get enough protein for building 
purposes and at the same time avoid an excess 
of waste material. 

Growing children need more protein than 
grown people. They must not only replace 
old building material, but they must also pro¬ 
vide building material for new growth. They 
must have material to repair the old building 
and at the same time bricks for the additions. 
For this reason the diet of children should con¬ 
tain a larger amount of protein in proportion 
to other elements than that in the diet of grown 
people. Milk, the natural food of the infant, 
contains a small amount of protein in proportion 
to other elements, because nature did not intend 
infants to grow very rapidly. Mother’s milk 
contains a smaller proportion of protein than 
does the milk of the cow, since nature intended 


HEALTH READER 


294 

that the calf should grow more rapidly than the 
human infant. 

When children reach the age of six or seven 
years they begin to grow rapidly. Then cow’s 
milk is better for them than the milk that was 
suitable when they were infants. There should 
be an abundance of protein in the food of a 
child during the period of rapid growth, which 
usually is between the ages of seven and seven¬ 
teen years. After the seventeenth year the 
amount may be diminished with safety. 

A STUDY OF CARBOHYDRATES 

What is the function of the starches and sugars 
contained in foods? Starches and sugars make 
up the greater part of human foods so far as 
weight and bulk are concerned. The chief, 
function of the carbohydrates (starch and sugar) 
in the body is to produce heat and energy. At 
the same time the carbohydrates aid in the 
digestion of other food substances and in chang¬ 
ing them into the form in which they are used 
for building tissue. They also aid, to a certain 
degree, in forming fat tissues in the body. 
Because starch and sugar produce heat and 
energy when consumed or burned in the body, 
the carbohydrates are called fuel. 

Nature intended that all the different classes 
of food—protein, carbohydrates, fats and oils, 


HOW DO WE GROW? 


295 


minerals, and condiments—should be present in 
the ordinary processes of digestion. Not the 
carbohydrates alone but every class of food 
exerts a profound influence on the relations of 
every other class in the process of digestion. 
Thus the nutritive value of any class of food 
can be studied only in the relation of that class 
to the nutritive value of all the other classes. 

What foods are particularly rich in starch and 
sugar? When we speak of a starchy food we 
naturally think of the potato, which consists 
almost entirely of starch. It is true that the 
potato contains a small quantity of protein, 
a considerable quantity of mineral substances, 
and a slight trace of oil. But all these things 
together form only two or three per cent of the 
weight of the potato, while the starch, including 
the small amount of sugar combined with it, 
forms from sixteen to eighteen per cent of the 
weight. The remainder is water and indi¬ 
gestible fiber. 

There are other foods containing about the 
same proportion of starch as the potato. Among 
these are arrowroot and cassava. These prod¬ 
ucts grow chiefly in tropical and semi-tropical 
regions, while the potato grows in temperate 
and north-temperate regions. Closely related 
to the potato are the so-called sweet potato and 
the yam. These also contain large quantities 


296 


HEALTH READER 


of starch, together with considerable quantities 
of sugar. 

Among the cereals, rice contains by far the 
greatest amount of starch, about eighty per cent 
of the rice grain consisting of starch. Among 
the other cereals, Indian com contains the 
largest amount of starch, and oats probably 
the smallest. But all the cereals contain con¬ 
siderable quantities of starch. The amount 
ranges from eighty per cent in rice to sixty-five 
per cent in oatmeal. Thus we see that the 
principal food product in cereals, so far as 
quantity is concerned, is starch. 

There are many prepared foods in the market 
that are almost pure starch. Among these 
we find tapioca, cornstarch, cassava starch, and 
arrowroot. They are used extensively in pre¬ 
paring puddings and custards. So far as value 
is concerned, such foods are excellent for the 
production of heat and energy. They also aid 
other food substances in the work of promot¬ 
ing growth and restoring tissue, though they 
are themselves of little value in that work. 

The starch used in this country is produced 
principally from corn. In Europe the principal 
source of starch is the potato. 

As we grow up our need for carbohydrates 
increases. This is a natural result of the greater 
demands made on the system for heat and 


HOW DO WE GROW? 


297 


energy, furnished so abundantly by the carbo¬ 
hydrates. Thus the proportion of starch and 
sugar in the diet of the grown person should be 
much greater than the proportion found in 
milk, which is the ideal food for .the infant and 
the child. 

How can the carbohydrates aid in digesting and 
preparing other food elements for use in the body? 

This is easily explained. The human body 
requires a varied diet, consisting of the five 
classes of food elements already mentioned. 
This is a normal or natural requirement. The 
different organs of the human body can do their 
work best only when the food elements are of 
the normal quality and in normal proportions. 
Any departure from this must necessarily be 
more or less injurious to the whole system. 

The truth of this is evident in sickness, when 
it is necessary to alter the proportion of the 
different classes of foods in the diet in order to 
meet the conditions brought about by the 
disordered functions of the body. In some 
diseases it is advisable to reduce considerably 
the quantity of carbohydrates (sugars and 
starches) in the diet. If this restriction is 
carried to a certain degree, improvement takes 
place. On the other hand, if the carbohydrates 
are entirely taken away the effect may be, and 
usually is, decidedly harmful. 


298 


HEALTH READER 


In building a house various materials are 
required — wood, lime, sand, stone, bricks, nails, 
iron and lead pipes, and furnaces. When the 
proper amount of all materials is used the result 
is a house of good appearance and quality, suit¬ 
able to live in, and comfortable. The result 
would be quite different if some materials were 
left out altogether and others were used in 
excessive quantities. If bricks were used with¬ 
out mortar, the house would soon fall to pieces. 
If too much wood were used, the house might 
take fire from the furnace, and so with every 
other material used in building the house. This 
is an illustration of what happens when we eat 
too much of one kind of food and not enough of 
another. Our foods should be so selected as 
to furnish all the materials needed, and all in 
the correct proportion for the proper develop¬ 
ment and growth of the body. 

A STUDY OF FATS AND OILS 

How are fats and oils used in body building ? A 

considerable proportion of the foods we eat, 
both vegetable and animal, consists of fats and 
oils. The terms “fat” and “oil” apply to the 
same substance, although there is a distinct 
difference between the two. The term “fat” 
is applied to a solid fat, that is, a fat that is 
solid at the temperature of the human body. 


HOW DO WE GROW? 


299 


The term “oil” is applied to a liquid fat, that is, 
a fat that is liquid at the temperature of the 
human body. Most vegetable fats are liquid 
and most animal fats are solid. Fats and oils 
are formed of essentially the same elements that 
exist in the carbohydrates. 

What is the function of oils in nutrition? Oils 
aid digestion because their flavor and taste 
make the foods in which they are present taste 
good. But the chief function of oil and fat in 
nutrition is to furnish heat and energy. Oil 
or fat furnishes a greater amount of heat than 
any other element of food. 

Does an excess of fat in the tissues of the body 
shorten human 
life? This ques¬ 
tion cannot be 
answered defi¬ 
nitely in regard 
to any one of 
us. So many 
things influence 
the length of 
human life that 
we cannot dis¬ 
cover with any 
certainty the influence of one thing alone. 
Studies have been made comparing the length 
of life of a great many persons. From these 



A boy of overweight and a boy properly 
proportioned 



300 


HEALTH READER 


studies it has been estimated that if a man 
six feet tall weighs two hundred forty pounds, 
that is, fifty to seventy-five pounds more than 
he ought to weigh, we may expect that his life 
will be shortened by about four years. 

What is the proper weight for grown persons of 
a given height? Various authors have constructed 
tables to show the proper weight for grown 
persons of a given height. The table below 
gives the average weight of men and of women 
of all ages combined from 15 to 70 years at a 
given height, and also the average increase in 
weight for each inch in height. 


HEIGHT 

MEN 

INCREASE IN 
LBS. FOR EACH 
INCH IN HEIGHT 

WOMEN 

INCREASE IN 
LBS. FOR EACH 
INCH IN HEIGHT 

4 ft. 9 in. 



Il6 

4 

10 in. 



Il8 

2 

11 in. 



120 

2 

5 ft. 0 in. 



122 

2 

1 in. 

129 - 


124 

2 

2 in. 

131 

2 

126 

2 

3 in. 

133 

2 

129 

3 

4 in. 

137 

4 

132 

3 

5 in. 

141 

4 

I36 

4 

6 in. 

145 

4 

140 

4 

7 in 

149 

4 

144 

4 

8 in. 

153 

4 

148 

4 

9 in. 

157 

4 

152 

4 

10 in. 

162 

5 

156 

4 

11 in. 

168 

6 

159 

3 

6 ft. 0 in. 

174 

6 

l62 

3 

1 in. 

180 

6 



2 in. 

186 

6 




Adapted from Medico-Actuarial Mortality Investigation, Vol. I, 1912. 









HOW DO WE GROW? 


301 


A STUDY OF THE BALANCED RATION 

What is meant by a balanced ration? When 
building a house the builder always begins by 
making an estimate of the exact amount of 
every kind of material that will be needed. It 
would be very foolish for him to buy a great 
quantity of lumber and bricks and not buy any 
sand, mortar, and nails. So the wise builder 
calculates very carefully the quantity of each 
kind of material he must have in order to com¬ 
plete the building. As a result, when he begins 
his work he will have on hand just the right 
amount of all materials, even to the paints, 
varnishes, and trimmings. When his work is 
completed there will be very little building 
material left over. 

At the same time the wise builder always tries 
to make certain that he has enough material. 
It would be better for him to have a little too 
much than not enough. To have too little of 
any one kind of material might be very costly, 
since the whole work would have to be delayed 
until the additional material could be bought. 
The house builder, in other words, secures his 
material in such quantities that he has enough 
of each and every kind, no matter how small 
or how large a quantity is necessary for the work 
that is to be done. 

This principle holds good in supplying food 


302 


HEALTH READER 


material for building up the body. We must 
endeavor to supply all the necessary materials, 
and in such quantities that there will be neither 
too much nor too little of any kind of material. 
We' then have what is called a balanced ration. 
Yet, as in the case of the house builder, it is 
better to have a little too much than not enough 
of any single article. But such excess should be 
limited to the smallest possible amount, so that 
after the food is consumed and digestion is 
complete, very little waste will be left. In this 
way the needs of nutrition will be well and fully 
satisfied. 

How many kinds of materials are required for 
body building? It has been estimated that from 
twelve to fifteen different substances are re¬ 
quired in the process of nutrition. Some of 
these things are similar in character to the 
paints, varnishes, decorations, and trimmings 
used in the building of a house. To leave them 
out would have little effect on the strength of 
the building, but neither the building nor the 
body would be quite complete or wholly pre¬ 
sentable without them. 

If we select our common food products wisely, 
and in the correct proportions, we secure all 
the twelve to fifteen substances needed in nutri¬ 
tion. If we do not use wisdom and judgment 
in our selection, some essential substances will 


HOW DO WE GROW? 


303 


probably be overlooked. The result will be a 
body that is weak and out of proportion. 

What essential materials are commonly omitted ? 
Among those commonly omitted are the mineral 
substances, so essential to the proper building 
of the body. In preparing our foods we usually 
throw away the portions that contain much 
mineral substance. The peelings of apples, 
potatoes, and other vegetables, the bran of 
wheat, oats, and corn, and the germs of cereals 
all are rich in oil and phosphorus. With the 
minerals we also reject the life-giving vitamines 
present in the outer coverings of these foods. 

Usually the statement of a balanced ration 
contains no reference to the mineral constitu¬ 
ents or the condiments. Yet to supply these 
substances is not only advisable but absolutely 
necessary. From one and one-half to two per 
cent of the total daily ration should consist of 
minerals, chiefly lime and phosphoric acid, with 
small quantities of potash, iron, soda, iodine, 
and magnesia. This requirement will be ful¬ 
filled if we eat foods no part of which has been 
discarded or greatly altered in the process of 
preparation. 

Why should condiments be used? We should 
next consider the necessity for condiments. 
The condiment used in largest quantities is 
salt. As in the case of other useful substances, 


304 


HEALTH READER 


an excess of salt is injurious. No more salt 
should be used than is necessary for proper 
relish or seasoning purposes. Salt is used with 
some foods and not with others. It is used, 
almost universally, in bread, with vegetables 
and meats, and in butter and cheese. On the 
other hand, we do not usually put salt on 
fruits or in milk. 

Other condiments, such as peppers, spices, 
and mustard, are commonly used with meats. 
Some are used with eggs and vegetables, espe¬ 
cially in salads. These condiments are gener¬ 
ally added in small quantities, otherwise the 
foods would be too strongly seasoned to suit 
the taste. Wood smoke, as you have already 
learned, is a condiment used in curing meats, 
such as ham and bacon. This condiment has 
a double purpose; it preserves the meat from 
infection by insects and bacteria and also adds 
a flavor that is well liked. 

With the exception of salt, the condiments 
form a very small proportion of pur food. 
Probably they do not exceed one twentieth or 
one fifteenth of one per cent of the total ration. 
The precaution with regard to the use of salt 
applies to the use of all condiments. They 
should all be used sparingly, just enough prop¬ 
erly to stimulate the glands that supply the 
digestive fluids. 


HOW DO WE GROW? 


305 


What should be the relative proportions of the 
chief food ingredients? Assuming that the min¬ 
eral substances and condiments are present in 
the correct quantities, we must now consider 
the correct proportions of proteins, carbohy¬ 
drates, and fats in a balanced ration. Experi¬ 
ence as well as a careful study of the food supply 
of human beings under various conditions and 
in various countries has revealed the quantities 
in which these food substances should be present 
in order to make a balanced ration. 

The standard ration of dry food for a man 
weighing one hundred fifty pounds is nearly one 
pound and a half, or 640 grams. For a ration in 
which there is a generous proportion of protein, 
this 640 grams should consist of 120 grams of 
protein, 440 grams of carbohydrates (sugar and 
starch), and 80 grams of fat or oil. This is con¬ 
sidered the proper proportion of ingredients in a 
well-balanced ration. 

Specialists in the study of diets have a way of 
determining whether a ration is properly bal¬ 
anced. They multiply the number of grams 
of fat by two and one quarter. To this prod¬ 
uct they add the number of grams of carbohy¬ 
drates. Then they divide this sum by the 
number of grams of protein. The quotient thus 
secured is called the nutritive ratio. Applying this 
rule to the standard ration of dry food given on 


306 HEALTH READER 

the preceding page, we get the following results: 

80 multiplied by 2% = 180 
440 added to 180 =620 

620 divided by 120 = 5.2 

This quotient (5.2) is the standard nutritive 
ratio. Assuming that there is the needed quan¬ 
tity of mineral matter and condiments in the 
ration, this quotient, 5.2, tells us that we have 
a standard ration in which the ingredients are 
present in the correct proportions. If we should 
decrease the amount of fat to 60 grams, and in¬ 
crease the carbohydrates to 450 grams and the 
protein to 130 grams, so as to make the same to¬ 
tal, 640 grams, we would then have this problem: 

60 multiplied by 2% = 135 
450 added to 135 =585 

585 divided by 130 = 4.5 

This quotient is less than the quotient (5.2) 
which has been taken as the standard nutritive 
ratio, and so we have what is called a “narrow 
ratio,” meaning one with too much protein. 
On the other hand, if the quotient obtained by 
some other arrangement is more than 5.2, we 
may conclude that we have what is called a 
“wide ratio,” or a ratio in which there is an 
excess of carbohydrates and fats. The wide 
ratio is best suited for men who work at hard 
physical labor. The narrow ratio is best for men 
engaged in less active physical labor, for those 


HOW DO WE GROWf 


307 


b z . 


4T 


who sit a good deal, and for those who do not 
wish to increase their weight. But any great 
variation from 
the standard 
nutritive ratio 
is more or less 
dangerous to 
health. Among 
those nations 
whose nutri¬ 
tive ratio com¬ 
monly is wide, 
that is, if the 
nutritive ratio 
runs from 7 to 
9, as in Spain, 

Greece, and 
Italy, the people are small in stature. If the 
ratio is narrow, as in the United States, Canada, 
and Australia, the people are large in stature. 

How can people unacquainted with principles of 
nutrition select a ration of a standard nutritive ratio ? 
Experience and the natural taste or instinct of 
the human being usually result in the selection 
of a diet that is well balanced. Persons in 
moderate circumstances who live in countries 
where food is abundant usually select a ration 
that approaches very closely the ideal, well- 
balanced ration. 




An American and a Greek 











HEALTH READER 


308 

The tendency to-day is toward a wider ration 
than is advisable, because many food substances 
extremely rich in protein, such as the outer 
layers and the germs of cereal grains, are re¬ 
jected in preparing the cereals for food. As a. 
result of the casting out of these materials we 
are eating larger quantities of starch and sugar 
than nature intended we should. Unfortu¬ 
nately, this excess of starch generally results 
from the exclusion of a large part of the pro¬ 
tein, oil, and mineral substances which naturally 
are present in our foods. 

Is it advisable to weigh the quantity of foods we 
eat? No. To sit down at the table with our 
thoughts occupied with the theories of eating, 
and then worry about how much of each kind 
of food we ought to eat, and what we ought not 
to eat, detracts greatly from the pleasure of 
eating, a sensation of great importance to diges¬ 
tion. We also interfere with digestion by con¬ 
centrating our thoughts on subjects that are 
not likely to promote the digestive processes. 
We should be confident that those who provide 
us with food will provide what is best for us. 
Our natural tastes, corrected or supplemented 
by good manners, will prevent us from being 
gluttons, but still we should all know whether 
we are eating too little or too much of this or 
that food. 


HOW DO WE GROW? 


309 


Moreover, ordinary experience in serving 
foods leads to a knowledge of how to regulate 
the quantity 
that each one 
should eat. 

The judicious 
mother always 
takes care that 
the child who 
is served first 
does not get 
too much and 
the others too 
little. The 
quantity each 
one receives, 
though not 
measured or 



Weighing bread 


weighed, is usually the amount each one ought 
to have. We should find it extremely annoying 
if at every meal we had to measure in a bal¬ 
ance or measuring cup the exact amount of 
solid or liquid food we were to have. 

Is there any great danger from eating without 
weighing or measuring the food? Only under 
special circumstances is there any very grave 
danger from eating without weighing or meas¬ 
uring food. If a child is very hungry he is 
likely to ask for more of the food that is served 



3io 


HEALTH READER 


first in the course of the meal than he ought to 
have. As a rule, good manners at the table 
correct this tendency. It is not good manners 
to ask for a second helping except under special 
conditions. In well-regulated families there is 
very little danger of overeating. 

What is a good rule to observe when eating? A 
good rule, if it can be conveniently followed, is 
to eat only one thing at a time. If we like a 
food for its taste and flavor there is no reason 
for depriving ourselves of that taste and flavor 
by eating it together with some other article of 
food. If we like the taste of meat, why do we 
want to mix it with that of potatoes? If we 
like bread, why should we destroy its taste by 
eating it with sirup? The French, who are 
recognized as authorities on foods and cooking, 
eat their vegetables apart from their meats. 

Fish is one of the foods that should never be 
eaten with anything else except the condiments 
that are usually used in preparing such foods. 
No food so effectually destroys the character 
and flavor of other foods eaten with it as fish. 
No other article of food, not even the customary 
potato, should be eaten with fish. Even the 
knives and forks used and the plates on which 
it was served should be removed and not used 
for any other food. 

Fowl as well as fish, though perhaps in less 


HOW DO WE GROW? 311 

degree, is better when eaten alone. It is 
customary to eat cranberry sauce with turkey. 
As a matter of fact, turkey tastes much better 
without it. Fowls of all kinds are commonly 
served with “stuffing,” that is, a dressing made 
chiefly of bread crumbs seasoned with condi¬ 
ments and placed inside the turkey and roasted 
with it. The turkey would really taste better 
without it. A gravy made from the juice 
which drips from the fowl while it is roasting 
is often served. There may be some excuse 
for this, because the flavor of the gravy is de¬ 
rived from the fowl itself, but you will get the 
most enjoyment out of fowl by eating it alone. 
Pork, especially fresh pork, is commonly served 
with apple sauce. There seems to be no special 
reason for this except custom. Vegetables also 
best serve their purpose as foods when eaten 
alone. 

But there are some articles so closely asso¬ 
ciated with each other that they are hardly 
to be considered as separate foods. I refer to 
the use of butter on bread or potatoes and the 
use of sirup and butter on hot cakes. In these 
cases the butter and the sirup provide necessary 
elements that are not present in the foods to 
which they are added. 

At dinner to-day or to-morrow try eating 
the various articles of food separately. After 


3 1 2 


HEALTH READER 


taking a few meals in that way you will appre¬ 
ciate the value of the practice. You will be 
able to appreciate the real excellence of each 
food and enjoy its taste to the utmost. You 



Sociability promotes digestion 


will also have simplified your diet, a very neces¬ 
sary thing for proper nutrition. 

What relation has sociability to eating? To par¬ 
take of food and drink with companions is one 
of the pleasures of social life. If a friend should 
happen to visit you, near the hour of the day 
when food is commonly served, the simplest 
dictates of friendship lead you to invite him to 
join you in the meal. One of the chief func¬ 
tions of social life is the dinner to which friends 
are specially invited. At social gatherings of 















HOW DO WE GROW? 


3i3 


any kind — the meeting of a literary society, 
a musicale, a card party, or any similar gather¬ 
ing — it is customary to serve refreshments 
toward the close of the evening. The offering 
and receiving of food is a universal mark of 
friendship and good will. 

The more pleasant the associations at the 
table, the more perfect are the workings of the 
digestive organs. Lightheartedness, pleasant 
conversation, and delightful companionship all 
promote digestion. On the contrary, care and 
worry, disagreeable companions, and quarreling 
interfere with digestion. For this reason, when 
we come to the table cares of every kind should 
be put aside, all bickerings suppressed, and all 
trouble as far as possible forgotten. 

QUESTIONS TO HELP THE PUPIL 

1. Where does the young plant get its first nourish¬ 
ment? Tell how you can show this. 2. When this 
supply is used up, where does it get its food? 3. What 
is necessary for life and growth? 4. Name the five 
principal classes of foods for animals. 5. In what other 
ways may foods be classified? 6. From what do we 
get most of the minerals in our food? 7. What vege¬ 
table contains a great deal of iron? 8. What propor¬ 
tion of our food should be mineral? 9. Why is it better 
not to discard the outer covering of fruits, vegetables, and 
cereals? 10. What food gives us the largest amount of 
protein? n. Name other foods which contain much 
protein and some vegetables that contain little. 12. How 
can we get the exact amount of protein that we need? 
13. Do proteins differ in nutritive value? 14. To what 
may we compare the body? 15. What are the best 


11 


314 


HEALTH READER 


protein bricks with which to build? 16. Why are rich, 
prosperous nations apt to use too much protein? 17. 
Why do growing children need more protein than grown 
people? 18. Between what ages should children have 
an abundance.of protein? 19. What is the function of 
the starch and sugar contained in foods? 20. Besides 
producing heat and energy, what do the carbohydrates 
aid in forming in the body? 21. What common article 
of food contains a great deal of starch? What is the 
proportion? 22. What is the principal food element in 
cereals? 23. Name the leading starch-bearing cereals. 
Which contains the least? 24. What prepared foods can 
we get that consist almost entirely of starch? 25. At 
what age are carbohydrates needed most? 26. What is 
a varied diet and why is it best? 27. Does the builder 
of a house get the exact amount of every kind of material 
necessary to complete it? why? 28. Does this prin¬ 
ciple hold good in supplying material for body building? 
29. W r hat is the difference between an oil and a fat? 
What is their chief function? 30. What is meant by a 
balanced ration? 31. What would happen to a house 
if the builder had not used enough nails or mortar? 
3 2. What are the most essential food materials ? 33. How 
many different substances are needed for body building? 
Which one of the essential materials is commonly omitted ? 

34. What caution should we observe in the use of condi¬ 
ments? What proportion of our food should they form? 

35. What is the standard ration of dry food for a man 
weighing one hundred fifty pounds? 36. How should 
these 640 grams be proportioned? 37. Can you tell how 
to determine whether a ration is well balanced? 38. 
What is the “standard nutritive ratio”? a wide ratio? 
a narrow ratio? 39. For what persons is a wide ratio 
best suited? a narrow ratio? 40. Is any great varia¬ 
tion from the standard dangerous? 41. What usually 
governs the selection of a diet that is well balanced? 

42. Tell why it is not well to mix foods when eating. 

43. What articles are usually not considered as separate 
foods? 44. Why should there be good cheer at the table? 
What sort of feelings interfere with digestion? 


XXVII. The Process of Digestion 

What is digestion? Before foods can be used 
in building new tissue, in restoring wornout 
tissue, and in creating heat and energy, they 
must be broken up and dissolved so that the 
useful elements in them may be absorbed into 
the blood stream and carried with it to every 
part of the body. This is the work of digestion, 
a long and complicated process requiring deli¬ 
cate machinery (organs) and thousands of tiny 
workmen (enzymes). 

THE TEETH AND THEIR FUNCTION 

Why do we chew our food? To be properly 
digested, food must first be reduced to very 
small particles. Liquids of course require no 
chewing, nor do such foods as soft puddings or 
mashed vegetables, except enough to separate 
them into smaller quantities. 

The action of the teeth and the jaws is some¬ 
what similar to the primitive or old-fashioned 
method of grinding grain between an upper and 
a lower millstone. In grinding grain only one 
of the millstones moves; similarly in chewing, 
only one of the jaws moves. In milling, how¬ 
ever, it is usually the upper stone that moves, 
while in chewing it is the lower “stone.” 

3*5 


HEALTH READER 


316 

The work of the teeth and jaws is of the 
greatest importance in aiding the process of di¬ 
gestion. So every one should know how to take 
care of his teeth in order that they may do their 
work thoroughly and well. 

Does the lower jaw move in more than one 
direction? Yes, the lower jaw has two distinct 
motions: first, the motion up and down, by 
which the food is cut into pieces; and second, 
the motion from side to side, by which the food 
is ground between the surfaces of the teeth. 

Do the teeth in different parts of the mouth have 
different functions? Yes. The front teeth are 
useful particularly in cutting the food into 
small pieces. They are, in other words, the 
cutting or incising teeth, and so are called 
incisors . By means of the front teeth we cut 
off a piece of food as large as we desire, and then 
reduce it to smaller pieces. The back teeth 
are called molars , derived from a Latin word 
meaning “to grind.” When we cut off a piece 
of food with our front teeth the motion of the 
lower jaw is straight up and down. Thereafter, 
when the food is placed between the molars, 
the motion is up and down and also sidewise, 
in order both to cut and to grind the food. 

What are temporary teeth? At birth human 
beings have no teeth. The infant has no need 
for teeth. The only food he should have is 


THE PROCESS OF DIGESTION 


3 i 7 


milk, and milk, we know, requires no masti¬ 
cation (chewing). At about the fifth or sixth 
month the first of the temporary teeth appear. 
These are the incisors or front teeth. Usually 
four of them come at about the same time, two 
in the upper jaw and two in the lower. Other 
teeth appear from time to time until, at the 
age of one year, the infant usually has eight 
teeth, four above and four below. 

The total number of temporary teeth that 
appear in a child’s mouth is twenty: four 
incisors, two canine or dog teeth, and four 
molars appear in the upper jaw and the same 
number in the lower jaw. The first temporary 
molar teeth usually appear from the twelfth 
to the fourteenth month, the temporary canine 
teeth from the fourteenth to the twentieth 
month, and the temporary back molars from 
the eighteenth to the thirtieth month. 

The child begins to lose these teeth, which 
are called the milk teeth, from the fifth to the 
seventh year. At the same time the permanent 
molars back of the temporary molars begin to 
show. By the eighth or ninth year the tem¬ 
porary teeth are nearly all gone, and by the 
fifteenth to the seventeenth year most of the 
permanent teeth have appeared, except those 
farthest back in the mouth, which are called 
wisdom teeth. Sometimes these teeth do not 


HEALTH READER 


318 


appear until after the age of twenty-one, and 
sometimes not at all. 

What is the composition of the teeth? That 
part of the tooth projecting outside the gum is 
called the crown and is covered with a hard, 
flinty substance called the enamel. Below the 
gum there is no enamel, 
but in place of it is a hard, 
bony substance called 
cement. Inside of the 
enamel and the cement 
is the tooth substance 
itself, the dentine as it is 
called. In the center of 
the dentine is a cavity 
filled with the soft sub¬ 
stance in which are the 
nerves and the blood ves¬ 
sels of the tooth. 

The dentine or ivory 
of'the tooth is composed 
of practically the same 
elements as the bones of the body. But it is 
much denser and for that reason much harder 
than the bones. About twenty-eight per cent 
of the elements in dentine consists of substances 
containing nitrogen, and the remaining seventy- 
two per cent of mineral matter. 

The enamel, or hard outer surface of a tooth, 



Vertical section of a tooth 
a, crown; b, neck; c, root; d, 
enamel; e, dentine;/, pulp cavity; 
g, gum; h, cement; i, jaw bone 









THE PROCESS OF DIGESTION 


319 


contains about the same elements as dentine, 
but the proportion of minerals is much higher, 
thus making the enamel still harder than the 
dentine. The minerals make up about ninety- 
six per cent of the enamel substance. 

The teeth are set into little holes or sockets 
in the jaw bones. That part of the tooth 
resting in these sockets is called the root. The 
front teeth have only a single root, while the 
side teeth have two roots and the back teeth, 
or molars, usually have three roots. These 
roots extend into the bony structure of the 
jaws, holding the teeth in place with great 
firmness, so that they may do their work as 
millstones without danger of becoming loose. 
The part between the crown of the tooth and* 
the root is called the neck of the tooth. This 
part is covered by the gum. 

What does “cutting the teeth” mean ? The term 
“ cutting the teeth” is applied to the process 
which takes place when the teeth erupt or come 
through,— that is, when they first show through 
the gum. This process really is cutting the 
gum and not cutting the teeth. In the infant 
the gum is closed; that is, there is no opening 
through which the teeth can come. When 
the teeth erupt they must push their way 
through the gum. Though this is a natural 
process, the tooth growing very slowly and 


320 


HEALTH READER 


the gum gradually disappearing in the path of 
the growing tooth, it is attended with tenderness 
and pain, and is often the cause of considerable 
irritation of the digestive organs. 

“Teething” is a process which mothers look 
forward to with anxiety, especially if it takes 
place during hot weather. Children that are 
born in the late spring or early summer have 
the advantage over those bom in the middle 
of winter, since their first temporary teeth ap¬ 
pear in cold weather and so cause less danger and 
disturbance than in the case of children whose 
teeth come during the summer. 

When the teething process begins it is cus¬ 
tomary to give the child some soft elastic 
substance on which to bite. The light rubber 
animals so commonly used as toys are excellent 
for this purpose, but they should be pasteurized, 
that is, heated for twenty minutes every day in 
water at a temperature of at least one hundred 
sixty degrees. This process makes the rubber 
safe for the child to use, and does not injure 
its texture. 

But the child should not be permitted to do 
this for more than a few days. The tissues of 
the infant’s mouth are very soft and yielding, 
and those who are constantly putting objects 
into their mouths, or who suck their thumbs, 
are likely to have deformed mouths, projecting 


THE PROCESS OF DIGESTION 


321 


teeth, and distorted nostrils. These things may 
lead to mouth breathing. There is also danger 
of carrying disease germs into the mouth. 

What care should be taken of temporary teeth? 
The temporary teeth require as much care as 
the permanent teeth. They are extremely im¬ 
portant to the health of the child from infancy 
to the age when the permanent teeth appear. 
This period covers a number of years and 
during that time the child must depend on his 
temporary teeth for chewing. This period is of 
the greatest impor¬ 
tance to the child, 
since then may be 
laid the foundation 
for lasting good 
health and for a 
strong and efficient 
body. 

A great' many 
people do not know 
what a serieus men¬ 
ace imperfect tem¬ 
porary teeth are to the health of the child. 
If a temporary tooth starts to decay, the parent 
is usually consoled with the thought, “Very 
well, let it go. The new tooth will soon take 
its place.” Such indifference is extremely dan¬ 
gerous. If the temporary tooth is lost before 



Teeth of seven-year-old child. The 
milk teeth are shaded. Permanent 
teeth are shown growing at the roots 
of the remaining temporary teeth. 


322 


HEALTH READER 


its time, there is danger that the permanent 
tooth following it will not develop properly. 
The germs of the permanent teeth develop early; 
so, if a temporary tooth is lost before its time, 
the germ of the permanent tooth will seek to 
occupy the vacant space. The germs of the 
permanent teeth on either side may also seek 
to grow into this open space. 

For these reasons every care should be taken 
in developing and preserving the temporary 
teeth as well as the permanent teeth. 

How may good teeth be developed ? Good health 
and the right kind of food are necessary for the 
development of good temporary and permanent 
teeth. The food should be rich in bone-building 
and tooth-building material. For this reason 
the diet of the child should contain plenty of 
mineral substances, particularly lime and phos¬ 
phoric acid. Milk is an ideal diet for the child, 
since it contains lime and phosphoric acid in 
the proportions needed to build up the bones 
and the teeth. 

When the child begins to eat solid foods and 
take less milk, it should eat the foods containing 
the necessary amount of mineral substances. 
The minerals, as we have already learned, are 
most abundant in the outer coverings of cereals, 
vegetables, and fruits. So when we throw 
away the skins of vegetables and fruits, and 


THE PROCESS OF DIGESTION 


323 


the fibrous coverings of the cereals, we deprive 
ourselves of mineral foods that are necessary 
for the development of the teeth. Young 
children cannot very well eat the skins of 
fruits or of potatoes. But the coverings of 
cereals, if ground very fine, are suitable foods 
for them. By using the proper kind of mill¬ 
stones the outer coat of the grain is so ground 
that it easily yields its mineral matters in the 
digestive process. Children should therefore 
be fed liberally with bread made from the 
whole grain ground fine in the old-fashioned 
way. Modern mills using smooth steel rollers 
do not grind the bran but break it into large 
flakes. In this form the bran is not suitable for 
digestion by children nor even by grown people. 

How do bad teeth endanger the health? Many 
dangers threaten the health of those who have 
poor teeth. Children, especially, are in danger. 
Children with poor teeth cannot chew their food 
properly. The food can be cut and ground 
into small particles by the process of chewing 
only when the teeth are in good working order. 

Moreover, it is of great importance that 
chewing should be done so thoroughly as to mix 
the saliva with every particle of food. The 
saliva aids the process of swallowing and pro¬ 
vides the additional moisture necessary to pre¬ 
pare the chewed mass for digestive purposes. 


3 2 4 


HEALTH READER 


The digestive substance {enzyme) contained in 
saliva rapidly changes starch particles in the food 

into a substance 
called dextrin and 
sugar. This is the 
first step in the 
digestion of starch 
foods. If the proc¬ 
ess of chewing is 
continued the en¬ 
zyme in the saliva 
will convert much 
of the starch into 
dextrin and sugar. 

What other dangers result from bad teeth? Many 
kinds of injurious bacteria lodge in decaying 
teeth. This is true especially if the decay 
extends down into the roots. If pus is formed 
it may easily be absorbed into the blood, caus¬ 
ing very serious results. 

It is almost impossible to keep a decaying 
tooth clean. It is hard to get at the decayed 
spot, which is often located between the teeth or 
concealed just below the gum. Even if we 
could reach the spot it would be difficult to 
remove the bacteria from it. Thus every de¬ 
caying tooth, and every tooth that is so deformed 
that it cannot cut or grind the food as it 
should, threatens health. 



THE PROCESS OF DIGESTION 


325 


How may we avoid these dangers? We must 
first discover the nature of the trouble. The 
teeth may be irregular and uneven. Very 
often the upper teeth project out of place. In 
early life such teeth may gradually be brought 
back into place by a skillful dentist. Very 
often two growing teeth are trying to occupy 
the same position. If it is too late in life to 
bring them back into place, one of them, the 
one that is farthest out of place, should be ex¬ 
tracted, leaving the remaining tooth to be 
brought into its proper position. 

Unfortunately the cost of bringing badly 
placed teeth into the proper position is too 
great for persons in ordinary circumstances. 
For this reason it is very important for the 
parent to make sure that proper care is taken 
of the temporary teeth, and so guard against 
deformities. 

In nearly all cases it is possible to save the 
teeth from early decay by inspection, cleanliness, 
and prompt attention to the first signs of decay. 
Careful attention to this matter is the duty of 
every parent. It is also the duty of every young 
person to form the habit of keeping his teeth 
thoroughly clean. 

What is the purpose of dental inspection in the 
public schools ? The purpose of dental inspection 
in the public schools is to discover the condition 


326 


HEALTH READER 


of each child’s teeth and the nature of the tooth 
trouble, if there is any. In order that the school 
may best serve its purpose — that the children 
may learn their lessons, obey their teachers, 
and remain in good health — the teeth of every 
child must be inspected and dental troubles 
corrected. The dental inspector furnishes a 
card showing the character of the disease or 
deformity. The child brings the card to the 



A school dentist inspecting a child's teeth 


parent, who then takes it ’to the family dentist. 
By means of this card the dentist will know at 
once where to look for the trouble. 

Parents who are not able to pay for such 
services can go to the public dental clinic, which 
provides free treatment. Such clinics are of 
the greatest importance to a community, and 
no village or city should be without one. 


THE PROCESS OF DIGESTION 


327 


Many children in the public schools have 
never had their teeth examined by a dentist. 
In many cases the parents, even, do not examine 
their children’s teeth and do not know their 
condition. Experience has shown that when 
tooth troubles are remedied, great improvement 
takes place in scholarship, deportment, and 
health. It is almost useless to try to teach 
children whose teeth are bad. Rather than 
try to teach such children, a determined step 
should be taken to save their teeth. If neces¬ 
sary, the teaching should be entirely discon¬ 
tinued until the teeth are saved. A child can 
learn his lessons next year, but he can never 
get back the teeth he loses. 

Careful dental inspection and prompt atten¬ 
tion to the faults it reveals, together with public 
support of a clinic for the children whose parents 
are unable to pay for such work, are of great 
importance to the welfare of every community 
and the success of every school. 

THE SALIVARY GLANDS AND THEIR FUNCTION 

What are the salivary glands? The salivary 
glands are little sacs connected with the mouth 
by small ducts or tubes. They secrete the fluid 
called saliva. The saliva is constantly entering 
the mouth through these tubes, but the flow is 
especially abundant during the time of eating. 


328 


HEALTH READER 


The saliva contains, as we have learned, an 
enzyme valuable in the digestion of starch. 

There are three pairs of salivary glands. 
The largest pair lie one on each side near the 
ears. They are called the parotid glands, the 
word parotid meaning “near the ear.” In the 
grown person they vary from one half ounce 
to an ounce in weight. The ducts through 
which the saliva enters the mouth are about 
two inches and a half in length. 

The pair of salivary glands next in importance 
is situated one on each side under the lower 
jaw in the upper part of the neck and are known 
as the submaxillary (under the jaw) glands. 
The third pair of salivary glands is situated 
under the tongue. They are called the sub¬ 
lingual (under the tongue) glands. 

The salivary glands are abundantly supplied 
with arteries, veins, and nerves. They are 
active at all times, but become very active when 
we are hungry, when we smell a good dinner, or 
when we sit down before an appetizing meal. 
You have all heard of the mouth “watering.” 
This means that the salivary glands are pouring 
a large amount of saliva into the mouth in an¬ 
ticipation of the good food which the sense of 
smell or of sight has discovered and reported. 
New saliva is always gathering in the glands to 
take the place of the fluid that is discharged. 


THE PROCESS OF DIGESTION 


329 


The gland under the tongue may be regarded 
as one gland, although, since it is divided by 
the middle line of the tongue, it is practically 
two separate glands. For the discharge of 
saliva, the gland under the tongue has a large 
number of ducts, varying from eight to twenty, 
each with a separate opening into the mouth. 

Constant chewing, especially of a substance 
that tastes good, will cause the glands to dis¬ 
charge large quantities of saliva. But such 
continuous activity of the glands cannot be 
regarded as desirable. The function of the sal¬ 
ivary glands should not be wasted by chewing 
gum or any other useless substance. When 
they are abused in this way, the glands become 
overworked and worn out, and so become un¬ 
fitted to play their part in aiding the processes 
of digestion. 

A STUDY OF SWALLOWING 

How do we swallow our food ? When the food 
has been well masticated and thoroughly mixed 
with saliva, the natural tendency is to pass it 
back toward the base of the tongue in the form 
of a bolus (ball). From the base of the tongue 
it passes into the opening of the esophagus , the 
tube situated behind the windpipe and lead¬ 
ing from the mouth to the stomach. The bolus 
is then swallowed. The process of swallowing 


330 


HEALTH READER 


cannot be controlled by the will. It is invol¬ 
untary or automatic. The fibers of the esopha¬ 
gus contract involuntarily and force the food 
into the stomach. You can keep the food from 
getting into the esophagus, but once it is there 
you cannot by any force of the will prevent 
yourself from swallowing it. 

If the food, instead of going into the esopha¬ 
gus, should enter the passage to the lungs, 
violent protests would result, in the form of 
coughing. This is the means nature takes to 
drive the unwelcome substance away. Should 
the food become fixed or fastened in the open¬ 
ing of the trachea (windpipe) the supply of air 
would be cut off from the lungs and death 
would follow. 

Instead of swallowing, does the esophagus ever 
work the other way ? Yes, in certain cases of sick¬ 
ness nature often reverses the act of swallowing 
and the food is forced up through the esophagus 
and out into the mouth. This is called vomit¬ 
ing. That process is also involuntary. We 
cannot prevent vomiting by means of the will. 
But we can cause it by irritating or tickling 
the throat, by taking medicine which produces * 
nausea or irritation of the stomach, or by drink¬ 
ing warm water, especially if it contains a little 
salt. Thus by mechanical means or by medi¬ 
cines we may aid the stomach in ridding itself 


THE PROCESS OF DIGESTION 


33i 


of substances which it cannot properly digest. 
The fibers of the esophagus reverse the action 
of swallowing and drive the food out again. 

Ruminant animals,—those that chew the cud, 
like the cow and the sheep,—are provided with 
a special stomach. This stomach receives the 
food in the form of boluses produced by the 
process of chewing. When this stomach is 
full and the animal stops eating, these boluses 
one by one are sent back into the mouth, where 
they go through a second process of chewing. 
When swallowed the second time, the bolus 
passes into a 


chewing 


second stomach. 

The human 
being is not pro¬ 
vided with any 
apparatus of 
this kind. We 
must, therefore, 
do our chewing 
well while we 
have the chance. Stomach of a cow ’ showing course offood 

Is it desirable to aid the process of swallowing 
by using liquids while chewing ? This question of 
the use of liquids while chewing has been the 
subject of much discussion. The best authori¬ 
ties generally oppose the use of liquids while 
chewing. They claim that such liquids lessen 




332 


HEALTH READER 


the activity of the salivary glands so that a 
decreased quantity of saliva is sent into the 
mouth. If we do not take liquids, and if we 
chew our food a little longer, greater quantities 
of saliva will be mixed with the food. This is 
especially desirable when eating starchy foods. 
When eating lean meats, eggs, and foods of that 
kind, it makes little difference whether the 
liquid required for the process of swallowing is 
' provided by the salivary glands or by drinking. 
But it is far better to do the chewing and 
swallowing first, and then, if more liquid is 
needed in the stomach, to drink afterward. 
If the liquid used is a food, as in the case of 
milk, the objections to drinking during the meal 
are largely removed. 

We have already called attention to the 
desirability of eating only one kind of food 
at a time. The same principle applies here. 
Swallow your food first; then drink afterward. 
But we must not forget that the food in the 
stomach must have a certain quantity of liquid 
mixed with it in order that it may be more 
easily acted upon by the digestive fluids. 

Good sense and good advice will lead children 
to take the proper amount of liquids during or 
after the meal. But such liquids* as coffee, tea, 
cocoa, chocolate, or beer should, of course, not 
be given to the child. 


THE PROCESS OF DIGESTION 


333 


THE FUNCTION OF THE STOMACH IN DIGESTION 

What is the stomach? If you follow the Detroit 
River as it flows south from Detroit you will 
soon come to where the river widens into a lake. 
About two hundred miles east it contracts and 
again becomes a river, which rushes over 
Niagara Falls. Lake Erie may therefore be 
regarded as an expansion in a river. The 
stomach bears much the same relation to the 
esophagus, or gullet, that Lake Erie bears to 
the Detroit River. It is an enlargement of the 
esophagus and has a shape somewhat similar 
to that of Lake Erie. 

The stomach is situated in the upper part of 
the abdominal cavity and is separated from the 
lungs and heart by a muscular partition called 
the diaphragm. 

The esophagus 
enters the stomach 
at a point near the 
heart, and there¬ 
fore the opening is 
called the cardiac 
(heart) orifice. The 
exit from the stom¬ 
ach, corresponding 
to the Niagara River, is called the pylorus. 

The size of the stomach varies with the size 
and age of the individual. In the adult of 



Human stomach showing cardia 
and pylorus 


334 


HEALTH READER 


ordinary size the stomach is about twelve 
inches in length and four inches in diameter at 
the greatest point. Its weight, empty, is about 
five ounces. In the infant the stomach is very 
small, and when distended is not able to hold 
much more than half a pint. In the adult the 
stomach can be stretched considerably and can 
hold large quantities of liquid 
and semi-liquid material. 

The inner coating of the 
walls of the stomach is a 
mucous membrane similar in 
character to the membrane 
inside the mouth and the 
esophagus. The walls of the 
stomach consist of four layers 
of muscular fibers that are 
capable of automatic move¬ 
ments, that is, movements not 
under the control of the will. 
It is by means of these au¬ 
tomatic movements of the 
stomach, and the movement 
Of the eSOphagUS in SWalloW- 
membrane; c, ’submucosa; ing, that the contents of the 

d, oblique muscular fibers; 

/; SSfflMSteiE stomach are kept well, mixed 

bers; g, peritoneum. and ^ gradually f orce d 

toward the pyloric opening, where they enter 
the small intestine. 



Enlarged section of 
the stomach wall 








THE PROCESS OF DIGESTION 


335 


Because fowls have no teeth, they are provided 
with a very strong and muscular stomach. 
Chickens and ducks eat large quantities of 
sand and gravel with their food, and these 
form millstones between which the solid grains, 
like wheat and corn, are ground into particles. 

The movements of the human stomach are 
very vigorous and they greatly assist the diges¬ 
tive processes. While these movements 'are 
automatic, they are influenced more or less 
by the state of mind of the individual. Atten¬ 
tion has already been called to the fact that 
pleasant conversation, agreeable companionship, 
and attractive surroundings promote digestion. 
In other words, these conditions stimulate the 
movements of the stomach and the activity of 
the glands which secrete the digestive ferments. 
On the other hand, anger, deep sorrow, or 
unpleasant surroundings interfere more or less 
with these movements, and the process of diges¬ 
tion is retarded or not properly performed. 
Sometimes the stomach is distended or stretched 
too much by overeating or drinking. This un¬ 
natural pressure tends to paralyze the muscular 
movements, and so interferes with digestion. 

If we could see the stomach during the normal 
process of digestion we should find, it going 
through all kinds of contortions, as if in pain. 
The fact of the matter is that these are normal 


336 


HEALTH READER 


churning movements performed in peace and 
comfort in the course of preparing the food for 
use in the body. 

In the mucous membrane in the stomach are 
the openings of the glands which secrete the 
digestive ferments. When examined with a 
magnifying glass the mucous membrane looks 
much like honeycomb, for there are many small 
and shallow depressions. In these are the open¬ 
ings through which the fluid containing diges¬ 
tive ferments enter the stomach. This fluid is 
known as gastric juice. The word gastric is de¬ 
rived from the Greek word meaning “stomach.” 

What digestive ferments are most active in the 
stomach? There are two principal digestive 
ferments in the gastric juice. In children’s 
stomachs a ferment is secreted which has the 
power of coagulating or curdling milk. This 
ferment is known as rennin. If milk remained 
in a perfectly liquid state in the stomach it 
probably would be expelled before it could be 
properly digested. Nature avoids this by con¬ 
verting the liquid milk into a mass of partly 
solid flakes. In this form the milk is retained 
in the stomach until the flakes are dissolved. 
In the manufacture of cheese, a substance called 
rennet extracted from pigs’ stomachs is used to 
curdle the milk. 

As we grow older, the amount of rennin which 


THE PROCESS OF DIGESTION 


337 


is secreted decreases. Nevertheless, as soon 
as we drink milk, and some of us drink milk 
all our lives, the rennin plays an important 
part as a digestive ferment. 

The other important digestive ferment in 
the stomach is pepsin , a digestive fluid active 
in the digestion of protein, converting it into a 
substance called peptone/ 

In the gastric juice is also an acid, known as 



Converting the white of an egg into peptone 


hydrochloric acid, which has important functions 
in the process of digestion. 

We may illustrate the first step in the diges¬ 
tion of protein as it takes place in the stomach 
by a simple experiment. If we heat the white 
of an egg it hardens. If we now add pepsin 
and a little hydrochloric acid to this sub¬ 
stance, and keep the mixture at the same 
temperature as that of the body, namely, 
ninety-eight and a half degrees, we shall see 
the white substance gradually dissolve. Soon 
all of it seems to have passed into solution, and 










338 


HEALTH READER 


we know that the protein in the white of the 
egg has been converted into peptone. 

This same process takes place in the stomach 
and is the principal digestive function of the 
stomach. Though the food in the stomach 
may consist of a mixture of proteins, starches, 
sugars, and fats, practically the only element 
that undergoes extensive digestion in the stom¬ 
ach is the protein. 

The enzyme in the saliva, as we have already 
learned, begins to act upon starch as soon as 
it enters the mouth. Then when the starch 
has been swallowed, the hydrochloric acid in 
the stomach secretion gradually brings the 
activity of the saliva to a stop. This is because 
the saliva is alkaline , that is, it contains lime, 
magnesia, and soda. The enzymes found with 
these substances cannot act when they come in 
contact with acids. But it is probable that be¬ 
fore their activity has been brought completely 
to a stop by the acid, most of the starch has 
been converted into dextrin and sugar. 

The ordinary fats are not digested in the 
stomach, but they are probably churned up and 
mixed with other foods by the movements of 
the stomach walls. 

How do the digestive ferments act? No one 

can tell how the digestive ferments act. The 
enzymes themselves cannot be digested. They 


THE PROCESS OF DIGESTION 


339 


are little workmen who tear down or alter the 
structure of the food. We know that this work 
is done, probably with the aid of water (hydroly¬ 
sis). We know it can be accomplished only by 
means of these ferments, that the ferments take 
an active part in the process, and that they are 
not living beings but belong to a class of sub¬ 
stances known as activators or excitors. We 
have learned in our study of vitamines (page 
179) that such accessories or excitors exist in 
certain foods, but they are not ferments. 

What causes the flow of digestive fluids? You 
have already been told how the salivary glands 
are excited or stirred to action, especially at 
the thought or sight or odor of good food. All 
these sensations cause a flow of saliva. The 
activity of the glands of the stomach is also 
excited somewhat by the odor and taste of 
foods, but their activity is caused mostly by 
certain properties of the foods themselves after 
they have reached the stomach. 

Among the foods that are most active in 
exciting the glands of the stomach are meats 
and meat juices. Among those that are less 
active are bread and the cereals. Experiments 
have shown that if bread is introduced into the 
stomach of a dog in such a way as not to sug¬ 
gest the idea of food, the digestive fluids of the 
stomach will not be secreted and the protein in 


340 


HEALTH READER 


the bread will remain undigested for a long time. 
Some foods, therefore, have more effective 
properties than others in directly exciting the 
flow of the digestive fluids. 

How much hydrochloric acid does the stomach 
contain ? After the stomach is emptied of food, 
and before it receives a new supply, it probably 
contains but little hydrochloric acid. But the 
healthy stomach is never free from the acid. 

The secretion of hydrochloric acid in the 
stomach is due to the same kind of excitation 
as that which produces the flow of the digestive 
ferments, pepsin and rennin. The acid first 
secreted after eating is absorbed by combining 
with the food. Gradually the acid permeates 
the food, and brings to a stop the action of the 
saliva on the starch in the food. After an hour 
or two the amount of acid increases and 
continues to increase until near the end of 
digestion, when the flow begins to stop. 

What is heartburn? Heartburn is the result of 
too much acid in the stomach. In some forms of 
indigestion, usually caused by overeating or eat¬ 
ing certain kinds of foods, a greater quantity of 
acid is injected into the stomach than is required 
for digestion. This acid causes disturbance and 
pain. Since the stomach is placed near the 
heart, the trouble was thought to be in the 
heart and so was called heartburn. 


THE PROCESS OF DIGESTION 


34i 


Esophagus 


The proper remedy for heartburn is to avoid 
eating too much, and especially to avoid eating 
such highly spiced foods as fruitcake, plum 
pudding, and mince pie, which are very apt 
to affect some people in that way. Alcoholic 
drinks of all kinds, especially beer or wine, 
also have that effect on many people. Such 
articles should 

Jl 1 

Duodenum \ 


be avoided in 
order to bring 
about a per¬ 
manent cure. 

The exit of 
food from the 
stomach. The 
foods, which 
have gone 
through the 
process of 
chewing in 
the mouth 
and partial 
digestion and 
mixing in the 
stomach, are 
now in the 
form of a 
thick liquid called chyme. 
from the stomach a little 



The intestines 

This liquid passes 
at a time into the 


342 


HEALTH READER 


small intestine through the opening known as 
the pylorus. At the pylorus is a fold in the 
mucous membrane. This fold, opening and 
closing like a valve, prevents the liquid chyme 
from passing too rapidly from the stomach into 
the small intestine. 

How long does the food remain in the stomach ? 

Under ordinary circumstances the stomach is 
practically empty in from three to four hours 
after eating. In infants, who get nothing but 
milk, the digestive process goes on more rapidly; 
after two and a half hours the infant’s stomach is 
practically empty. For this reason infants and 
children should be fed more frequently than 
grown people. Infants may be given six or 
seven meals a day. Children from two to five 
years of age may be given four or five meals a 
day. Above the age of five we can usually get 
along with three meals, and grown persons 
not engaged in hard labor can get along very 
well with two meals. 

A STUDY OF THE SMALL INTESTINE 

What is the small intestine? The small intes¬ 
tine is a channel quite unlike that of a river 
in that the farther it is away from its begin¬ 
ning at the pylorus the smaller it becomes. 
The reason for this is clear. As the food 
enters the small intestine, and the process of 


THE PROCESS OF DIGESTION 


343 


digestion continues, the food is gradually 
absorbed and hence decreases in quantity on 
its way through the small intestine. 

The first part of the small intestine is about 
as long as the breadth of twelve fingers, and so 
is called the duodenum , from a Latin word mean¬ 
ing “twelve each.” At first it passes slightly 
upward from the stomach, then curves down¬ 
ward, approaching the spinal column. There is 
no very distinct mark to show the end of the 
duodenum and the beginning of the next portion 
of the intestine, which is called the jejunum. 

The jejunum gets its name from a Latin 
word meaning “empty,” because it was always 
found to be empty after death. The jejunum 
is about eight feet ]ong, that is, about two fifths 
of the length of the small intestine. It is laid 
in convolutions or folds, so that it may lie 
within the cavity of the abdomen. 

The third portion of the small intestine, 
the ileum , has its name from the Greek word 
meaning “to twist.” It is distinguished by its 
numerous convolutions or coils. It is nearly 
twelve feet long, about three fifths of the whole 
length of the small intestine. In a grown per¬ 
son of ordinary size the small intestine is about 
twenty feet long. 

What is the function of the small intestine? As we 

have learned, the principal digestive function of 


344 


HEALTH READER 


the stomach is to reduce the protein materials 
in the food to the form of peptone. The func¬ 
tion of the saliva is to start 
the digestion of the carbo¬ 
hydrates (starch and sugar). 
The completion of the di¬ 
gestive process now takes 
place in the small intestine. 

In the duodenum the food 
is mixed with two impor¬ 
tant digestive secretions. 
One of these is the bile or 
gall. The bile is separated 
from the blood by the organ 
called the liver. The bile 
The gall bladder collects in a pouch called the 
feflctehomiiver^fhepa* g oil bladder and is transmit- 
ted through a tube opening 

aticduct; h, duodenum . 1 1 1 

into the duodenum about 
midway in its length. The other important 
digestive fluid consists of the secretions from 
a gland called the pancreas . These secretions 
also enter the duodenum. 

The bile and the secretions from the pancreas 
are alkaline, and so overcome the acidity of the 
food as it passes through the duodenum. The 
food thus first becomes neutral , that is, neither 
acid nor alkaline; later it becomes alkaline as the 
amount of alkaline fluid in the intestine increases. 



THE PROCESS OF DIGESTION 


345 


A STUDY OF THE LIVER AND THE PANCREAS 

What is the liver? The liver is one of the 
largest organs of the body. It is situated on 
the right side, immediately under the diaphragm. 
The liver of a full-grown person in good health 
weighs from 
three to .four 
pounds. It is 
from ten to 
twelve inches 
long, and six 
or seven inches 
wide, and about 
three inches 
thick in its 
thickest part. 

The liver is 
divided into 
two principal parts, the right and left lobes. 
There are also three smaller lobes. 

The liver is provided with a remarkable series 
of blood vessels (arteries and veins), for in addi¬ 
tion to its function of separating the bile from 
the blood it brings about many changes in the 
nutrients which are carried to it in the blood. 
We have been told how the proteins and the 
carbohydrates digested in the small intestine are 
carried to the liver by way of the portal vein. 
In the liver these products undergo further 



The liver 


12 


346 


HEALTH READER 


changes and are then sent out to all parts of the 
body by way of the blood stream. The liver 
bears practically the same relation to the intro¬ 
duction of nutriment into the body as do the 
lungs to the introduction of oxygen into the body. 

The amount of sugar circulating in the blood 
is determined by the liver. This amount is 
very small. Most of the sugars that are formed 
by the digestion of the carbohydrates in our 
food are not needed for immediate use. So, 
instead of being sent into circulation all at 
once, they are stored away after being changed 
by the liver into a sugar-producing substance 
known as glycogen. Glycogen may be regarded 
as a reserve supply of carbohydrates. Little by 
little it is changed back again into sugar and 
sent into the blood, where it is burned accord¬ 
ing to the needs of the body. Thus we see 
that it is not necessary to eat sugar or starch 
constantly in order to supply fuel to the body, 
for when we eat more than is needed at a certain 
time the excess is at once stored away to be 
used at another time. 

Glycogen is not stored solely in the liver. It 
is found elsewhere, especially in the muscular 
tissues of the body. In certain kinds of meat, 
such as that of the horse and the lobster, there 
is a large amount of glycogen, so much so indeed 
that such meats taste sweet. The liver also 


THE PROCESS OF DIGESTION 


347 


changes into sugar certain products of protein 
digestion. 

What other important function has the liver ? 

The liver has a very important function as an 
excretory organ. Bile, for instance, which is 
secreted by the liver, is largely a waste prod¬ 
uct, though it also has important digestive 
functions. Urea, which is excreted in the 
urine, is also manufactured chiefly in the liver 
from the final products of the digestion of 
proteins. The kidneys separate it from the 
blood and pass it on to the bladder, whence 
it is excreted. 

What is bile? In one sense bile is a waste 
product, separated by the liver from the blood 
for the purpose of eliminating it from the body. 
In the second place it has important digestive 
functions and in many ways performs the same 
functions as pepsin in the stomach and the 
secretions of the pancreas. 

The formation of bile in the liver is probably 
a continuous process. But it is not poured 
continuously into the small intestine. In man 
and in some animals it is stored up in the gall 
bladder, from which it is poured through a duct 
into the duodenum. 

What is the pancreas ? The pancreas is a long, 
narrow gland lying in the upper part of the 
abdominal cavity near the duodenum. The 


348 


HEALTH READER 


secretions from the pancreas enter the duodenum 
through a tube or duct which unites with the 
duct leading from the gall blad< 4 er. The daily 



The pancreas 


quantity of secretions from the pancreas in a 
man of average size ranges from a little over 
a pint to almost a quart. 

What digestive ferments are secreted by the 
pancreas? One of the important digestive fer¬ 
ments in the fluid secreted by the pancreas is 
diastase or amylase. This has the same prop¬ 
erty as the enzyme called ptyalin in saliva, which 
we know begins the digestion of the carbohy¬ 
drates. Another important ferment from the 
pancreas is trypsin. This ferment acts on the 
peptone, the substance formed from the digestion 
of protein in the stomach. Thus trypsin is close¬ 
ly related to pepsin. The pepsin begins the work 
of digesting protein and the trypsin completes it. 

We have learned that the fats are not digested 


THE PROCESS OF DIGESTION 


349 


in the stomach. But when they enter the small 
intestine the third important ferment in the 
secretion from the pancreas, known as lipase or 
steapsin, begins the digestion of the fat foods. 

Thus it is seen that three separate kinds of 
digestion take place in the small intestine. The 
peptones are broken up by trypsin into elements 
called amino acids; the carbohydrates (starch 
and sugar) are broken up by the diastase or 
amylase into maltose (malt sugar), dextrose 
(right hand sugar), and levulose (left hand 
sugar); the fat is reduced by the lipase or 
steapsin to glycerin and fatty acids. 

All these dissolved products now form a 
milky fluid called chyle. In that form the foods 
are readily absorbed through the thousands of 
little vessels which line the walls of the small 
intestine. These vessels then carry the foods 
into a common stream that'is poured into the 
blood and so carried to every part of the body. 

A STUDY OF THE SPLEEN 

What do we know about the spleen? The 

spleen is situated on the left side, and very near 
the end of the stomach that is turned toward 
the heart. For many years the spleen was a 
mystery to those studying the growth and devel¬ 
opment of the body. It was thought to be an 
organ without a function, because it had no 


350 


HEALTH READER 


duct by means of which its secretions could 
reach any part of the intestines. By some it 


was thought to 
be the seat of 
bad passions, 
such as anger 
and envy. 



A later study 
of the spleen has 
brought out the 
fact that it goes 
through certain 
changes in size 
which keep step 
with the taking 
of food into the 


'Intestinal 

impression 


The spleen 


stomach and the process of digestion. After we 
have eaten, the spleen increases in size, continues 
to increase for several hours, and then slowly 
returns to its original size. Thus it is evident 
that in some way the spleen is in sympathy 
with, or is affected by, the process of digestion. 

The presence of certain substances in the 
spleen which are important in the nourishment 
of the body is another reason for believing that 
the spleen plays an important part in nutrition. 
The organ is also thought to have important 
functions in connection with the red corpuscles 
of the blood, for they seem to undergo certain 


THE PROCESS OF DIGESTION 


35i 


changes when in the spleen. But it is certain 
that of all the organs of the body of any size 
the spleen must be regarded as the least impor¬ 
tant, since it has been found that if it is cut out 
of the body, life is not necessarily endangered 
by its absence. Animals continue to live and 
remain apparently in good health after the spleen 
has been removed. 

In a grown person weighing one hundred 
fifty pounds, the spleen weighs approximately 
one half pound. In very old persons its weight 
diminishes in proportion to the weight of the 
body. In certain diseases it becomes much 
enlarged, and has been known in extreme cases 
to weigh twelve or fifteen pounds. 

We know less, perhaps, about the functions 
of the spleen than about the functions of any 
other important organ in the body. 

A STUDY OF THE LARGE INTESTINE 

What is the large intestine ? When the food 
has passed through the small intestine and 
most of the food elements have been absorbed, 
the remainder enters the large intestine, which 
may be described as a secondary stomach. A 
comparison has been made between the stomach 
and Lake Erie. In like manner the large intes¬ 
tine may be compared to Lake Ontario. The 
entire food canal, including the mouth, the 


352 


HEALTH READER 


esophagus, the stomach, the small intestine, and 
the large intestine, is known as the alimentary 
canal, alimentary being derived from a Latin 
word meaning “food” or “nourishment.” 

The first part of the large intestine resembles 
a pouch, and is called the caecum. Two folds 

of membrane 
guard the open¬ 
ing from the 
small intestine 
into the cae¬ 
cum, keeping 
the digested 
food from re¬ 
turning into 
the small intes¬ 
tine. 

The passage 
of the food 
through the 
small intestine 
is quite rapid. 
Now as it pours into the large intestine the rate 
of progress is at once greatly reduced. It is 
evident, therefore, that the object of the large 
intestine is to receive the contents of the small 
intestine and hold them until a convenient time 
for their excretion. 

In addition to the caecum, other parts of the 





THE PROCESS OF DIGESTION 


353 


large intestine are the ascending colon , so called 
because this part leads upward; the transverse 
colon , which crosses the abdominal cavity from 
one side to the other; and the descending colon , 
the part which leads to the end of the intes¬ 
tinal canal, the rectum. 

The caecum receives from the small intestine 
not only the excess food but also any remaining 
enzymes, alkaline substances, and waste prod¬ 
ucts that may be present. If there is any un¬ 
digested food, the digestive ferments carried 
with it into the large intestine may continue 
their work for some time, though always with 
less and less activity. 

The principal material absorbed in the large 
intestine is water. The contents of the intes¬ 
tine therefore become firmer and harder as 
they pass upward through the ascending colon, 
across the body through the transverse colon, 
and down to the rectum through the descend¬ 
ing colon. At this point the contents of the 
large intestine are called feces . After the feces 
have been retained in the large intestine for a 
varying period of time, they are voided from 
the body, the final chapter in the complete his¬ 
tory of the food in its course through the body. 

Are active organisms present in the large intes¬ 
tine? The contents of the large intestine favor 
the development of vast numbers of very small 


354 


HEALTH READER 


organisms, known as bacteria . They exist in 
such enormous numbers that a considerable 
part of the feces in the rectum may be made 
up of these small vegetable growths. 

These bacteria act particularly on any remain¬ 
ing protein matter in the contents of the large 
intestine, forming products consisting of liquid, 
solid, and gaseous substances. The most impor¬ 
tant of these substances in regard to their effect 
on health are indol , phenol , and skatol. Phenol 
is the chemical name of carbolic acid. Indol 
is related more or less closely to indigo. Skatol 
is distinguished by its bad odor. 

These products pass into the blood to a large 
extent through the walls of the large intestine, 
and are finally separated from the blood by the 
kidneys and sent to the urine. All these prod¬ 
ucts are found in normal, healthy persons. 
They are regarded as dangerous to health if 
formed in too large quantities or if kept too 
long in the body. 

QUESTIONS TO HELP THE PUPIL 

i. Why must food be digested? 2. To what process 
can you compare the act of chewing? 3. Which jaw 
moves when you chew? 4. Which of the stones in the 
old-fashioned mill moves, the upper or lower? 5. What 
is the use of the front teeth? What are they called? 
6. What are the molars ? 7. At what age does the child’s 

first teeth appear? 8. How many temporary teeth are 
there? 9. Name other teeth besides the incisors and the 
molars. 10. When does the child begin to lose the 


THE PROCESS OF DIGESTION 


355 


temporary teeth? n. At what age have all the perma¬ 
nent teeth appeared? 12. What are “wisdom” teeth? 
13. What is the enamel of a tooth? the cement? 14. 
What is the principal tooth substance? 15. Where in 
the tooth are the nerves and blood vessels? 16. What 
is the function of the roots? 17. What are the uses of 
saliva? 18. Describe the salivary glands. 19. How does 
the saliva enter the mouth ? 20. What is an involuntary 

process? Name one. 21. Through what tube does the 
food pass to the stomach? 22. What would happen if 
the food should enter the windpipe? 23. What is another 
name for the windpipe? 24. What is a bolus of food? 
25. What animal chews the cud? How do the cow’s 
jaws move? 26. What is the diaphragm? 27. To what 
may we compare the stomach? 28. What is the ordinary 

size of an adult’s stomach? 29. Of how many layers do 
the walls of the stomach consist? 30. By what means 
is food mixed and sent on through the stomach to the 
pylorus? 31. What glands do we find in the mucous 
membrane lining the stomach? 32. What are the two 
principal digestive ferments in the stomach? 33. How 
does rennin act on milk? 34. What is the function of 
pepsin? 35. What acid is secreted in the stomach? 
36. May children be fed more often than grown people? 
why ? 37. What is the purpose of the fold at the pylorus ? 

38. What is the ordinary length of the small intestine in 
a grown person? 39. From what organs are digestive 
ferments sent into the small intestine? 40. Is the food 
acid or alkaline when it passes from the stomach into the 
small intestine? 41. How is it changed here? 42. What 

are the functions of the liver? 43. What is glycogen? 
44. From what is urea manufactured ? 45. What impor¬ 

tant digestive fluid is secreted by the liver? 46. How 
do the digested or dissolved food products get to all parts 
of the body? 47. Why was it believed that the spleen 
had no function ? 48. Where is the spleen located and 

how does it act during the process of digestion ? 
49. Why can the spleen be regarded as of little impor¬ 
tance? 50. What part of the intestines does the food 
enter after leaving the small intestine? 51. How does 


356 


HEALTH READER 


the rate of progress of the food change as it enters 
the caecum? 52. What is the main object of the large 
intestine? 53. What vegetable growths or organisms are 
present in the large intestine? 54. What is the work of 
these bacteria? 55. What work do the kidneys perform? 

56. What do we mean when we say a child is “cutting 
teeth”? 57. What is usually given the child when 
cutting teeth? What is the danger of this? 58. What 
is the danger of losing a temporary tooth too early? 
59. What food contains minerals in the proportions needed 
to build up bones and teeth? 60. Why is bread, made of 
the whole grain ground in the old-fashioned way, good for 
children? 61. Why must food be thoroughly chewed? 

62. What may lodge in the cavity of a decayed tooth? 

63. How may we avoid having bad teeth? 64. Have your 
teeth been inspected by the school dental inspector? 

65. What kind of food requires saliva for digestion? 

66. What is the best rule to follow in the use of a beverage 
at a meal? 67. Why does overeating interfere with the 
stomach movements? 68. What foods are most active 
in exciting the glands of the stomach? 69. What is 
heartburn? What causes it and what is the remedy? 


XXVIII. A Study of the Kidneys 


Vena cava 


What is the function of the kidneys ? The kid¬ 
neys are situated in the lower back part of the 
abdominal cavity, one on each side. They are 
connected with the bladder by excretory tubes. 
The function of the kidneys is to separate 
wastes from the blood and 
pour them into the bladder 
in the form of urine for 
excretion from the body. 

In the urine besides water 
is excreted the excess of 
mineral salts that have 
been taken in with the food, 
after they have served their 
function in the body; also 
the waste substance, urea, 
which is formed from the 
final products of protein 
digestion; the sulphuric acid 
compounds of indol, skatol 
and phenol; and finally uric 
acid. 

The principal constituent 
of the urine is urea. Urea, although a normal 
product of the breaking up of protein substances 
in the system, must be promptly eliminated from 



The kidneys , bladder , 
and ducts 


35 7 









358 


HEALTH READER 


the blood. It is to the kidneys that we owe 
our safety from acute and fatal poisoning with 
urea, as well as from other disorders. If the 
kidneys cease to act, as is the case in some 
diseases, death follows within a short time. The 
kidneys are therefore very important from the 
point of view of health. 

The kidney is about four inches in length, 
two inches in breadth, and one inch in thickness. 
The left kidney is somewhat longer and thinner 
than the right. The right kidney, however, is 
situated a little lower down in the abdominal 
cavity than the left, because of the large space 
required by the liver, which lies just above it. 

The excretory duct of the kidney is called the 
ureter. It leads from the kidney to the bladder. 
The duct leading from the bladder is called the 
urethra. The quantity of urine excreted is 
determined largely by the character of the diet 
and the amount of water, or other liquids com¬ 
posed chiefly of water, that the individual drinks. 

What are some of the common diseases of the 
kidneys ? There are two common diseases of the 
kidneys. These are very troublesome and dan¬ 
gerous and are due perhaps to causes entirely 
external to the kidneys themselves. We have 
learned that in the normal nourishment of the 
body the sugars are burned, forming chiefly 
carbon dioxide and water. Sugars, therefore, 


A STUDY OF THE KIDNEYS 


359 


are not found as normal excretions in the urine. 

There are certain conditions that may favor 
the appearance of sugar in the urine for a short 
time. For instance, the eating of enormous 
quantities of sugar may cause a temporary 
excretion of sugar in the urine. There are also 
certain temporary disorders, during which sugar 
may be excreted. In good health and with a 
well-ordered diet the sugar is entirely burned. 

There is a disease, called diabetes , which is 
characterized by the presence of large quantities 
of sugar in the urine. While it is usually spoken 
of as a kidney disease, it is more properly a diet 
disease. It can be controlled to a great ex¬ 
tent by diminishing the amount of sugars and 
starches in the food. 

We have learned that protein matter normally 
digested in the body is reduced to the form of 
amino-acids, in which form it is built up into 
the tissues of the body and finally broken into 
the substances composing urea. There are cer¬ 
tain disordered conditions of nutrition in which 
soluble protein, known as albumin, is separated 
from the blood through the kidneys and appears 
in the urine. This condition may be a dan¬ 
gerous form of disease and should receive 
prompt medical attention. The disease is known 
as Bright's disease from the name of the 
physician who first described it accurately, and 


360 


HEALTH READER 


is spoken of as a kidney disease, when perhaps 
the kidney is without blame in the matter and 
the trouble really comes from disordered con¬ 
ditions of nutrition. 

The proper functioning of the kidney and the 
proper evacuation of the bladder are necessary to 
health, and the principles on which the activity 
of these organs depends should be taught to all 
in order that health may be preserved. 

QUESTIONS TO HELP THE PUPIL 

1. Describe and locate the kidneys. 2. What is their 
work? 3. What disorder of the kidneys does eating 
large quantities of sugar sometimes cause? 4. What 
are two dangerous diseases of the kidneys? 5. What 
would be the result if the kidneys should fail to act? 
6. How large is the kidney? 7., Explain the connec¬ 
tion between the kidneys and the bladder. 8. What 
should be taught to all? why? 


XXIX. How Foods Are Absorbed 


How do nutrients obtained by the process of 
digestion pass into the blood ? It is not difficult 
to get a general idea of how the nutrients — sub¬ 
stances which promote growdh— obtained by 
the digestion of foods are absorbed. The 
whole alimentary canal is lined with what is 
known as mucous membrane. This mucous 
membrane constantly secretes a fluid consisting 
mostly of w r ater and containing a viscid (sir- 
upy or ropy) substance. This fluid is called 
mucus. Usually the mucus is colorless but 
sometimes, when secreted in large quantities 
or if secreted from certain membranes, it is 
milky or even yellowish in color. Mucus is 
necessary to the proper activity of the whole 
alimentary canal, aiding the digestive secretions 
from the stomach, the pancreas, and the gall 
bladder in dissolving the food substances. Any¬ 
thing that interferes with the normal secretion 
of mucus tends to cause or promote disease. 

In addition to the mucous glands and the 
openings through which the digestive secretions 
enter the intestines, the mucous membrane, 
especially in the small intestine, is supplied also 
with an extensive system of absorbing vessels. 
Thus substances pass in both directions through 
361 


362 


HEALTH READER 


the mucous membrane, the digestive ferments 
and the mucus entering the intestine, and the 
digested foods and water passing out. 

Are food products absorbed in the stomach? 
Though digestion takes place in the stomach, 
little food is absorbed there. On the other 
hand, certain substances that cannot be regarded 
as true foods are readily absorbed. The most 
important of these is alcohol. Water, which 
is so important to the digestive process, is not 
absorbed in any quantity through the walls of 
the stomach unless alcohol is present. Small 
quantities of certain sugars in our foods are 
probabfy absorbed, but it is doubtful whether 
this is true of any of the fats. 

Where are foods principally absorbed? The 
principal system of vessels provided for the 
absorption of food is distributed throughout 
the mucous lining of the small intestine. Slen¬ 
der projections, known as villi , cover this lining. 
In these are spread millions of tiny capillaries , 
which take up the products of the digestion of 
the carbohydrates and also of protein. These 
products are then conveyed into the blood stream 
and carried through a tube known as the portal 
vein leading into the liver. 

A portion of the sugar is retained in the blood 
and passes immediately from the liver to all 
parts of the body to be burned for the purpose 


HOW FOODS ARE ABSORBED 


363 


of producing heat. The remainder is converted 
into glycogen (sugar producer) and stored away, to 
be given up little by little in the form of sugar 
as conditions may require. The blood must al¬ 
ways contain a certain amount of sugar at all 
times. It has been estimated that a thousand 
parts of blood carry only about fifteen parts of 
sugar. For this reason one of the chief functions 



A lymphatic gland 


of the liver is to receive the whole mass of car¬ 
bohydrates (sugars) as they are digested, and 
send them into the blood in the proper quantities. 

How are the fats absorbed? A second system 
of absorbers is present in the villi. These are 
suited to the absorption of digested fats. They 
are called lymphatics , or lacteals from a Latin 
word meaning “milk,” because when the fats 
are absorbed they form a milky emulsion. 
The contents of the larger absorbing vessels 
become whitish in appearance when food con¬ 
taining a large quantity of fat is absorbed. The 
fats are carried through the lacteals into a large 
tube which in turn empties into the blood stream. 


364 


HEALTH READER 


There is no doubt that a part of the digested 
protein is absorbed by the same vessels that 
take up the fat, and that it enters the circulation 
together with the fat. In fact, it is not improb¬ 
able that neither system of absorbers is engaged 
exclusively in taking up a certain food product. 

While the greater part of our food is absorbed 
in the small intestine as described, we should 
not forget that the mucous membrane probably 
has a slightly absorbent effect throughout the 
alimentary canal, with the possible exception of 
the mouth and the esophagus. 

Are certain kinds of protein more easily 
absorbed than others? Experience has shown 
that certain proteins, especially those contained 
in milk and eggs, and to a certain extent those 
found in meats, are more readily and completely 
absorbed than some others. It is believed that 
ninety-five per cent or even more of the protein 
of milk, eggs, and meats, eaten in normal quan¬ 
tities, is digested and absorbed. 

On the other hand, the gluten of wheat, the 
zein of corn, and the hordein of barley are not 
absorbed so completely as the protein in milk 
or in meat. The protein in bran, especially, is 
not absorbed in large quantities. The reason 
for this difference lies not so much in the nature 
of the protein itself as in the fact that the 
vegetable proteins are incrusted with a substance 


HOW FOODS ARE ABSORBED 


365 


known as cellulose as well as with other sub¬ 
stances that are difficult of digestion (perBo¬ 
sons'), and so protect these proteins more or less 
from the action of the digestive ferments. 

How are mineral substances absorbed? The 
mineral substances we eat are doubtless 
absorbed in the various ways in which the 
proteins, the carbohydrates, and the fats are 
absorbed. Common mineral substances (salt, 
phosphates, lime) are not readily absorbed in 
the stomach unless they are present in large 
quantities, and it is not likely that common salt 
will be eaten by any one in very large quantities. 

The use of condiments in our food has a 
stimulating effect on the absorbent action of the 
mucous membrane of the stomach and doubtless 
also of the small intestine. 

QUESTIONS TO HELP THE PUPIL 

1. What membrane lines the inside surface of every 
portion of the alimentary canal? 2. What fluids are 
secreted by this membrane? 3. Where does the greatest 
absorption of food take place? 4. What are the villi? 
5. What are the capillaries and what is their, use? 6. 
What is the use of the portal vein? 7. What are the 
absorbers called that take up the fat and oil products? 
8. Why are these absorbing vessels called lacteals? 9. 
What duct or tube carries these products into the blood 
stream? 10. What proteins are most readily absorbed? 
11. Why are the cereal proteins not so easily absorbed 
as the proteins in milk, eggs, and meats? 12. How are 
mineral substances absorbed? 13. Do condiments aid 
absorption in the stomach? 


XXX. The Blood Stream 


What is the blood? The blood is the liquid 
which flows through the arteries and veins of 
the body, carrying nourishing materials with 
which to build tissues and to make them grow. 
It also carries the oxygen by means of which the 
heat and energy of the body are produced, and 
the mineral salts which maintain the blood in 
an alkaline condition and thus keep the muscles 
of the heart active in propelling the blood 
through the arteries. The blood also carries 
to the proper organs waste products, such as 
water, carbonic acid, urea, and used-up mineral 
salts. 

What are the chief constituents of the blood ? 

Water is the most abundant constituent of the 
blood, its proportion being nearly eighty-one 
parts in a hundred. Besides water, blood con¬ 
tains nitrogenous materials called plasma. In 
blood that has been removed from the body, 
the plasma hardens, forming what is called a 
“dot.” If the clotted blood is washed with 
water, a fibrous substance known as fibrin is 
separated from the other contents of the blood. 
It is found to be of a yellowish-white tint. The 
other substances in the plasma after the fibrin 
has been separated form a liquid called serum . 

366 


THE BLOOD STREAM 


367 


How soon does the blood clot after it leaves the 
body ? The blood of different individuals varies 
greatly in this respect. It also varies in the 
same person, according to the state of health. 
In some diseases the blood, when removed from 
the body, does not clot at all. In others, the 
blood clots while it is still in the body. In 
the latter case the clots lodge in the valves of 
the heart and death speedily follows. 

The usual time required for healthy blood to 
clot after it flows from the body is from five to 
ten minutes. 

What are other constituents of the blood? The 

blood is full of disk-like bodies of minute size 
which can be seen only with the aid of a mag¬ 
nifying glass. These bodies are called cor¬ 
puscles. They are of two kinds, the red disks 
and the white disks. The red disks are really 
the oxygen carriers of the blood, and the white 
disks are especially active in safeguarding the 
health of the body. They are the policemen 
already referred to. 

How do white corpuscles guard against disease ? 

The white corpuscles were for many years 
objects of much speculation. Their true func¬ 
tion was not known positively until a short 
time ago. The white corpuscles seem to have 
a life of their own, and to be able to govern 
their own movements. They do not remain at 


368 


HEALTH READER 


rest and are not satisfied to be carried along me¬ 
chanically by the blood stream, but make little 
journeys on their own account. It is believed 
that these white cells have the power to destroy 
the germs of disease which enter the blood. In 
other words, they act as policemen, and when a 
disease germ enters the blood it is their duty to 
arrest it and either drive it out or destroy it. 

What is the chief function of the blood? The 
blood of an animal, as the Bible says, “is the 
life thereof.” Blood and life mean almost 
the same thing. The blood stream is the life 
stream. The blood distributes to all parts of 
the body not only the materials that are neces¬ 
sary for growth and repair, but also those that 
provide heat and energy. The blood also carries 
the oxygen that is necessary to the vital func¬ 
tions. Finally it carries away the waste mate¬ 
rials from the broken-down tissues. 

The blood in a healthy state, flowing away 
from the heart through the arteries, carries a 
large volume of oxygen and carbon dioxide 
loosely combined with the coloring matter. 
It is then a brilliant red. When the blood 
returns to the heart through the veins it carries 
less oxygen but a very considerably increased 
quantity of carbon dioxide. This fact is demon¬ 
strated very beautifully by the change of color 
which the blood undergoes when it passes from 


THE BLOOD STREAM 


369 


the capillaries leading to the arteries to the 
capillaries leading to the veins. The change 
of color is from a brilliant red to a dull purplish 
blue. 

It is certain that the blood in a healthy state 
never loses all its oxygen, nor all its carbon 
dioxide. There is a normal minimum amount 
of carbon dioxide in the blood, and a normal 
maximum amount of oxygen. The venous 
blood carries approximately half its volume, or 
about forty-five per cent, of carbon dioxide. 
This is reduced to thirty-eight per cent in the 
arterial blood. 

If any very great change takes place in the 
blood to increase or diminish the minimum or 
maximum content of carbon dioxide or of 
oxygen, serious troubles or even fatal results 
may occur. Nature’s system of breathing pure 
air is the best known means of maintaining the 
proper balance. 

What happens when there is too much blood in 
the body? If both the volume of the blood and 
the soluble substances contained therein are 
increased beyond the normal because of an 
over-generous diet and the drinking of large 
quantities of liquids, a greater effort than usual 
is demanded of the heart. The pressure which 
the blood exerts on the heart and the arteries 
is increased. As the physician says, “the blood 


370 


HEALTH READER 


pressure is high.” The blood pressure may be 
very easily measured by wrapping the arm 
with a rubber or other air-tight envelope to 
which a delicate measuring instrument is at¬ 
tached. Air is now pumped into the air-tight 
envelope until a sufficient pressure is produced 
on the arm to stop the pulsation at the wrist. 
When the pulsation at the wrist can no longer 
be felt, the measuring instrument will give the 
measure of the blood pressure. 

In youth and in early life the blood pressure 
is usually very low. As we grow older, and the 
walls of the arteries get firmer, the blood pres¬ 
sure increases. If the arteries are diseased so 
that their walls are thickened and very much 
hardened, the blood pressure is increased. 
When the blood pressure reaches one hundred 
sixty millimeters of mercury we know either 
that old age is coming on, that there is too much 
blood, or that the artery walls are becoming 
too thick. A pressure of one hundred eighty to 
two hundred millimeters is evidence of a grave 
disease which must be carefully treated. In 
such cases, if the thickening and hardening of 
the artery walls has not proceeded too far, 
prompt relief may usually be gained by reduc¬ 
ing the diet, and especially by omitting meats 
and eating only simple cereals, fruits, nuts, and 
vegetables. 


THE BLOOD STREAM 


37i 


One of the principal dangers of a high blood 
pressure is the effect on the heart. The in¬ 
creased labor of the muscles of the heart and the 
pressure on its cavities cause the heart to enlarge, 
and such enlargement is usually dangerous. 

What happens if there is too little blood in the 
body? If the volume of blood in the body 
becomes less than normal, or if the blood is 
thinned by the extraction of any of its normal 
ingredients, the health of the body is endangered. 
The condition of the blood can be determined 
by measuring the blood pressure, and by a 
chemical and microscopic examination. If it 
is too thin, a great lessening of the coloring 
matter of the blood is often noticeable, showing 
that practically all the contents of the blood 
are becoming poorer in quality. This condition 
causes paleness, colorless lips, a cessation of 
growth, general apathy and indifference, a lack 
of desire for exercise or work, and inability to 
prepare lessons or to do any mental work. 
The name physicians have given to the trouble 
is anemia. 

Thin blood or too little blood is a very serious 
matter. In fact, it is a disease, and should 
receive careful medical attention. Usually some 
fault in the diet or disease of the organs of 
digestion is the cause of such disorder. A diet 
of fresh, clean milk, fresh eggs, fruits, vegetables, 


372 


HEALTH READER 


and fresh poultry or meat, properly cooked, will 
very often entirely remedy the trouble. 

What are “blood purifiers”? A great many pat¬ 
ent medicines claiming that they will purify the 
blood are offered for sale. ‘‘Purifying the blood” 
is a phrase that has no definite scientific mean¬ 
ing. The blood is said to be impure whenever 
it carries too much or too little food or the germs 
of disease. Impure substances in the blood are 
usually enzymes or are poisons produced by the 
work of bacteria. The blood may also carry 
certain organisms, for instance the germs which 
produce malaria or chills and fever. Other 
living organisms may be present in the blood, 
producing specific diseases. Thus any scientific 
method of purifying the blood must be based 
on an understanding of what the impurity is. 

It is evident that none but a scientific man 
who has made a specialty of the subject can 
discover whether there are impurities in the 
blood and what they are. This he does by means 
of certain chemical tests, with the microscope or 
in other ways. No one but the trained physi¬ 
cian who understands the nature of the disorder 
can prescribe for it. 

The common so-called blood purifiers are 
usually mild cathartics by means of which the 
alimentary canal is thoroughly evacuated; or 
they may consist of certain herbs and roots 


THE BLOOD STREAM 


373 


which have little or no effect in improving the 
condition of the blood. Beware of secret blood 
purifiers. As a rule they are fraudulent, and 
sometimes they are extremely injurious. 

What is the relation between the condition of 
the blood stream and “spring fever” ? An ex¬ 
pression commonly heard in many parts of the 
country is “ spring fever.” In the first warm 
days of early spring many people, both young 
and old, complain of feeling tired and lose all 
desire for active exercise or hard work, mental 
or physical. Strictly speaking, this feeling is 
not a disease, though it is called “spring fever.” 

The feeling of weariness in spring is due wholly 
to the increased temperature or to faults in the 
diet. In cold weather we should eat a much 
larger amount of food, especially heat-giving 
foods, than we do in warm weather. This is in 
order to supply additional warmth, since the 
heat of the body radiates, or is given off, so 
rapidly in the cold atmosphere. When spring 
comes on and it has grown warm, if we continue 
these habits of eating we consume more food 
than the blood stream needs. To rid the blood 
of the excess food the body uses up much of its 
vitality, so that one is likely to feel indolent 
and tired. 

As the warm weather comes on, the amount 
of food eaten, by grown people as well as by 


374 


HEALTH READER 


children, should be promptly diminished. This 
will in a measure prevent the feeling of weariness. 
The stimulation produced by the cold tem¬ 
perature of winter is also lacking in the warm 
days of spring, thus adding to the trouble. 

QUESTIONS TO HELP THE PUPIL 

i. What is the result of any change in the normal 
amount of carbon dioxide or of oxygen in the blood? 
2. What is a 4 ‘blood purifier”? 3. When is the blood said 
to be impure? 4. What is it necessary to know about a 
disorder of the blood before any one can prescribe a 
remedy? 5. Why should so-called blood purifiers be 
avoided? 6. How can the blood pressure be measured? 
7. Tell how you may find out if there is too little blood 
in the body. 8. What is the name of this trouble? 9. 
What diet is good in cases of anemia? 10. What is 
“spring fever”? 11. To what is this feeling of weariness 
due? 12. How may spring fever be prevented? 

13. What materials does the blood carry away from the 
lungs? to the lungs? from the digestive organs to 
the tissues? to the excretory organs, the liver and the 
kidneys? 14. What proportion of the blood consists of 
water? 15.. Of what does plasma consist? 16. What is 
the fibrous substance in the hardened plasma? 17. What 
remains when the fibrin is removed from the plasma? 
18. What do corpuscles resemble? 19. What is the 
function of the red corpuscles? of the white corpuscles? 
20. What is the color of the blood when it returns to 
the heart through the veins ? 21. What is the color of the 

blood when it is carrying a supply of oxygen through the 
arteries? 22. Does the blood lose all its carbon dioxide 
when it reaches the lung cells? 23. What is the normal 
minimum amount of carbon dioxide in the blood? 24. 
What is the effect on the heart and the arteries of too much 
blood? 25. What does a high blood pressure sometimes 
show as to the condition of the arteries? 26. What is 
the effect of high blood pressure on the heart? 


XXXI. A Study of the 
Nervous System 

THE BRAIN 

What are the functions of the brain? This is a 
very difficult question to answer, yet a perfectly 
natural one to ask. The brain is located 
within the skull. It is a mass of delicate tissue, 
arranged in lobes and folds, richly supplied with 
blood vessels, and covered with a heavy, tough 
membrane. That the brain is a very important 
organ is shown by the fact that nature has sur¬ 
rounded it with a fort or shield of bones to 
protect it from 
injury, blows, 
sudden changes 
in tempera¬ 
ture, and other 
harmful influ- 
ences. The 
shield of bones 
surrounding 
the brain is 

mnrp nr 1 pcc 4 section of the skull showing the brain 

II1U It Ui it da scalp; bt cerebrum; c> sku u ; dt cerebellum; 

spherical, and medulla oblongata 

is completely closed except for a number of 
perforations in the under surface and the sur¬ 
face toward the face. These openings admit 



375 


376 


HEALTH READER 


the spinal cord, various nerves, and the arteries 
and veins that carry blood to and from the 

brain. 

Although the 
term “skull” 
really includes 
all the bones of 
the head, it will 
be used in this 
discussion with 
reference only 
to that portion 
inclosing the 
brain. At the 
points most ex- 

The skull , showing the hones posed to dan- 

a, frontal; 6, parietal; c, temporal; d, sphenoid; cr o c 

e, malar; f, superior maxillary (upper jaw); do, lUT 

g, occipital; h, inferior maxillary (lower jaw); . . 

i, nasal: j, ethmoid; k, lachrymal instance, tile 

forehead and around the ears—the brain is pro¬ 
vided with additional protection. Between the 
bony layers of the forehead over the eyes is an 
open space, so that if you puncture or pierce 
the outer layer of bone the inner layer may still 
remain uninjured. The bones back of and 
around the ears are also thickened for purposes 
of protection. 

The outside of the skull is covered with the 
skin and the hair, which also aid in protecting 
the brain. 



A STUDY OF THE NERVOUS SYSTEM 377 


Altogether, there are twenty-two bones in 
the structure of the head. Eight of these 
form the skull, the 
shield inclosing the 
brain. In infancy 
the bones of the 
skull are not joined. 

Between them are 
spaces composed of 
flexible substances 
that gradually har¬ 
den into bones as ^ kul1 °f a Negro 

the child grows older. In the grown person the 
skull bones are usually so firmly united as to 
form practically a single bone. 

The skull varies in size. The skulls of edu¬ 
cated and civilized people are thought to have 
a larger capacity than 
those of ignorant or 
savage peoples. But 
the prevailing idea 
that the size of the 
brain indicates the 
amount of intelligence 
is by no means true. 
Yet idiots and others of 
arrested mental devel¬ 
opment usually have small brains while many 
men of great mental powers have large brains. 




13 


378 


HEALTH READER 


The brain is supposed to be the organ of 
mental activity. Our intellect, in other words, 
is so closely associated 
with the functions of 
the brain as to warrant 
the statement that in¬ 
telligence is -directly 
due to the working of 
the brain. You may 

Skull of a chimpanzee l ose y 0Ur foot Or your 

hand or your leg or your arm without in any 
way affecting your mental and intellectual 
vigor. But the moment the brain is attacked, 
intelligence diminishes, mental power decreases, 
and mental activity may cease altogether. 

The brain consists of four general divisions: 
First, the large brain, called the cerebrum , oc¬ 
cupying the greater part of the skull cavity and 
lying toward the front and the top of the skull. 
Second, the small brain, called the cerebellum , 
lying at the base and toward the back of the 
skull. Third, the expansion of the spinal cord 
within the skull, called the medulla oblongata. 
Fourth, the bridge-like structure at the base 
of the brain, called the pons from a Latin word 
meaning “bridge” and forming connecting links 
between its parts. 

What is the total weight of the brain ? In a grown 
man of average size the brain weighs about fifty 




A STUDY OF THE NERVOUS SYSTEM 379 


ounces. In a woman it weighs about forty- 
five ounces. The weight of the brain varies in 
different individuals, but usually the variation 
from these figures is not'more than about four 
ounces. Occasionally a man has been found 
with a brain weighing sixty-five ounces or more, 
and once in a while a woman with a brain 
weighing from forty-eight to fifty ounces. 

THE SPINAL CORD 

What is the spinal cord and where is it lo¬ 
cated? Next in importance to the brain is the 
spinal cord , a mass of soft tissue located in the 
backbone. The backbone, known also as the 
spinal column or simply as the spine , consists 
of a series of bones placed one above the other. 
Near the center of each bone is an opening, so 
placed as to form a continuous canal through¬ 
out the length of the column. This canal con¬ 
tains the spinal cord. 

Each of the thirty-three separate bones in 
the spinal column is called a vertebra. The 
continuous canal formed by the cavities in the 
vertebrae is not entirely circular, but more 
nearly of a triangular shape, especially toward 
the upper end of the spine. 

The top bone of the spine is called the atlas , 
after the mythological giant, Atlas, who was 
said to bear the world on his shoulders. The 


380 HEALTH READER 

skull rests on this bone as the round globe 
was said to rest on the shoulders of Atlas. 

The second bone from the top provides a 
movable joint on which the head may be turned 
from side to side, and for this reason 
it is known as the axis. 

The other vertebrae next in order 
are numbered third, fourth, fifth, 
sixth, and so on. 

The upper part of the spinal 
column is called cervical (neck), the 
middle part dorsal (back), and the 
lower part lumbar (loins). 

The vertebrae are joined together 
by elastic bands of tissue, called 
ligaments , in such a way that the 
spinal column may be bent from side 
to side, or forward and backward, 
without permitting the bones to 
move out of place. If one bone 
spinal column is displaced or injured so that the 
from s ide 1 ^ f orm of the central canal is changed 
b' thoracic* or interrupted in any way, the spinal 

d, sacrafP cord, the delicate nerve substance in 

e, coccygeal interior of the canal, would be 

injured or compressed. If this should happen, 
all parts of the body supplied by nerves having 
their origin in the spinal cord below the point 
of injury would be paralyzed. 









A STUDY OF THE NERVOUS SYSTEM 381 

There are two kinds of paralysis from which 
we may suffer. Paralysis may be caused by an 
injury to the brain, or by an injury to the 
spinal cord. In an injury to one side of the 
brain all of the opposite side of the body is 
paralyzed. But in an injury to the spinal cord 
both sides of the body below the point of injury 
are paralyzed. Thus in a case of paralysis 
any one who knows these facts can determine 
whether the trouble is 
due to an injury to 
the brain or to the 
spinal cord. 

What is infantile 
paralysis? The dis¬ 
ease known as infan¬ 
tile paralysis is the 
result of an infection 
of the spinal cord by 
bacteria, causing pa¬ 
ralysis. It attacks 
chiefly infants and growing children, though 
occasionally grown people fall victims to it. 
How sufferers become infected with the bacteria 
is not known and no remedy has yet been dis¬ 
covered. The disease is often fatal, and, even 
if the victim recovers, he may continue to suffer 
from partial paralysis. 

What is meant by curvature of the spine? The 



An improper sitting position 









382 


HEALTH READER 



backbone or spine in a normal, 
healthy individual is curved when 
viewed from the side. But it is 
straight when viewed from the 
back or from the .front. Some¬ 
times there is a sharp, abnormal 
bend in the spine. Such defor¬ 
mity is known as curvature of the 
spine. It is often caused by hab¬ 
its of holding the body improperly 
when sitting or standing. People 
who are seated when at work 
often have a slight curvature to the 

Improper position 1 K v fUp 

of the body when ierc > caused oy tne 

standing fact that the right 
side is used more frequently than 
the left. 

Most of the diseases of the 
spinal cord begin with an injury, 
received very often in play or 
in the course of violent exercise. 

Some children injured in this way 
may recover entirely, while in 
other children the injury may 
cause the development of tuber¬ 
culosis in the part of the spine __ 
that was affected. The result is ® 



permanent deformity and very improper position 
often early death. Any injury to ^ ^walking hen 





A STUDY OF THE NERVOUS SYSTEM 383 

the spine should at once receive the careful atten¬ 
tion of a competent physician. It is too serious 
a matter to overlook. Often grave deformities 
that cause lifelong suffering may be prevented 
by prompt attention to such an injury. 

Children should be cautioned against jumping 



from a great height down to a hard surface. 
The shock often causes an injury to the spine. 
Injury to the spine is also liable to occur in 
violent play, as in wrestling or in football play¬ 
ing. Football playing cannot be commended as 
an exercise for young children and is dangerous 
even for older persons. For young people such 
sports as baseball, tennis, running games, and 
swimming are greatly to be preferred to football. 

What are the nature and function of the spinal 
cord? The spinal cord is an essential part of 



384 


HEALTH READER 


the nerve system. It consists of two parts. 
The chief function of one part is to control 
physical movements; that of the other, to 
receive and carry sensation to the brain. The 
substance composing the spinal cord is similar 
to that of which the brain is made up. It is 
also somewhat similar to the substance com¬ 
posing the nerves, except that it is softer and 
more pliable. 

The spinal cord is' inclosed in a protecting 
membrane like that wrapped around the brain, 
and lies within a strong framework of bones. 

The spinal cord may be thought of as a 
continuation of the brain. While the brain is 
believed to have charge of our thinking proc¬ 
esses and sensations, the spinal cord is thought 
to be that part of the same system which has 
charge of our muscular movements and sensa¬ 
tions. When we are reading or studying, we 
are said to be cultivating our brains; when we 
acquire skill at play, or manual skill in such 
occupations as wood or iron working, or in 
playing upon a musical instrument, we are 
supposed to be educating the spinal cord. That 
scheme of development is best which includes 
the education of both the brain and the spine, 
so that we may become skilled in play, in work, 
and in exercise, and at the same time acquire 
knowledge. 


A STUDY OF THE NERVOUS SYSTEM 385' 


THE NERVES 

What are the nerves? The nerves are fibers 
connecting the brain and the spinal cord with 



Section through spinal cord showing nerves 
a, spinal cord; b, emerging posterior root; c, sensory nerve; 
d, motor nerve; e, emerging anterior nerve; /, gray matter; 
g, white matter 

every part of the body. They have the prop¬ 
erty of transmitting sensations of pleasure or 
of pain. They also control all muscular move¬ 
ments. 

As the nerves approach the surface of the 
body they become finer and branch out into 
numerous thread-like fibers. These are so nu¬ 
merous that it is difficult to prick the skin with 
a fine needle without touching a nerve and feel¬ 
ing a sensation of pain. This sensation of pain 
is supposed to be carried along the nerve 
filaments to the spinal cord in a way that is 
not well understood. The sensation passes on 
through the spinal cord to the brain, where it is 





386 


HEALTH READER 


registered as if it were a telegraphic message re¬ 
ceived at the end of a wire. Then another wave is 
sent back through the spinal cord and the nerve 
that controls the movements of the muscles. 

When your finger touches an object hot 
enough to burn, you quickly though not in¬ 
stantly receive a sensation of pain. This is 
immediately followed by a sudden muscular 
movement which withdraws your finger from 
the hot surface. But this does not happen in 
time to avoid a burn. If the transmission of 
the sensation through the nerve and the reply 
to the message had been instantaneous your 
finger would have been withdrawn before it was 
burned. This simple experience aptly illus¬ 
trates the phenomenon of the nerve functions. 

Can the speed with which messages are sent 
through the nerves be measured? The speed 
with which nerve force travels along the nerves 
can be measured, though not with absolute 
exactness. 

It has been estimated that the velocity of the 
nerve sensation in the adult human being is 
about 30.5 to 33 yards per second. The rate 
of transmission of sensation in infants is much 
slower than this, and in some animals the rate 
of transmission is even slower than in infants. 
In the lobster it has been discovered to be about 
six and a half yards per second; in fish the rate 



A STUDY OF THE NERVOUS SYSTEM 387 

is less than one fifth of a yard per second. 
But these figures are only approximate. All 
we can say definitely is that the movement in 
the nerve fiber, or the rate at which a sensation 
is carried along the nerve, is many thousands 
of times less rapid than the rate of transmission 
of a wave of electricity through a copper wire. 

What is the function of the nerves? The nerves, 
as we have learned, have two distinct functions. 
One is to carry sensations of all kinds—heat, 
cold, pain, pleasure — to the nerve centers; the 
other, to carry an impulse from the nerve centers 
to produce muscular contraction or movement. 
The nerves are the means of communication 
between our nerve centers, the spinal cord and 
the brain, and the external world. 

What are voluntary and involuntary movements ? 
If you decide to reach your hand out for a 
book, the impulse to take the book originated 
in the brain center by a strange and mysterious 
force that we call the will . This impulse was 
carried along the nerves to produce a certain 
motion. You reach out your hand and take 
the book as determined by your will. Such a 
movement is called a voluntary movement. 

On the other hand, if your finger happens to 
touch a hot stove there is an entirely different 
process. A message is sent from your finger 
to the receiving office in your brain that your 


388 


HEALTH READER 


finger is burning. Immediately a message is 
sent back to the muscle controlling your arm 
and hand to withdraw your finger from the 
stove. Such a movement is called involuntary. 
No person whose hand by chance comes in con¬ 
tact with a surface hot enough to burn it, can 
control this movement. It is true that by the 
exercise of your will you can deliberately place 
your hand on a burning surface and hold it 
there; that is, if your will is strong enough. 
But such an action is voluntary, while the action 
described is involuntary. 

The beating of your heart is evidently a 
motion caused by nerve control. But the im¬ 
pulses which cause this motion are produced 
without your control, and the motion that 
results cannot be stopped by mere force of will. 
The movement of the diaphragm in breathing, 
by means of which the air is taken into and 
sent out of the lungs, is also involuntary. It 
is true that by exercising your will you can 
hold your breath for a certain length of time. 
There may be instances of persons who have 
held their breath long enough to cause death, 
but this is not possible for the ordinary person. 

There is a distinct difference between the 
function of the nerves in carrying a sensation 
and in carrying an impulse for muscular move¬ 
ment. In other words, one kind of mechanism 


A STUDY OF THE NERVOUS SYSTEM 389 

is required for conveying a sensation and an¬ 
other kind for carrying an impulse to move a 
muscle. Separate wires—that is, separate nerve 
filaments—are provided which are connected 
with the spinal cord in different ways and at 
different places. The nerve filaments carrying 
sensations to the brain are called sensory nerves; 



those transmitting an impulse from the brain to 
the muscles are called motor nerves. 

The sensory-nerve filaments and the motor- 
nerve filaments are usually present side by side 
in all parts of the body wherever sensations 
are produced and movements required. But 
widely separate filaments may take part in 
connected sensory and motor processes. For 
instance, the sensation of burning the tip of the 
finger is transmitted by the very few sensory 
nerves affected by the burn. But the impulse to 
act is sent through all the motor nerves leading 












HEALTH READER 


390 

to the muscles of the arm and the hand and 
the finger. Thus, while the sensation of pain is 
transmitted by a very few nerves, the effort to es¬ 
cape the danger or pain comes back by hundreds 
of nerves, some of them widely separated. 

The action of widely separated sensory and * 
motor nerves may be illustrated in another 
way. The nerves of the eye are spread over 
a membrane at the back of the eye. When you 
see a person or object the sensation of sight is 
transmitted along the sensory nerves of the eye. 
In answer to that sensation, either you may 
start in the direction of the person or object or 
you may turn and run away from it. In either 
case the motor nerves in nearly all the muscles 
of the body are active as a result of the sensa¬ 
tion sent to the brain along the nerve of sight. 

The nerves branch out from the brain to all 
parts of the body in much the same way as 
the arteries branch out from the heart, and 
come back from all parts of the body in much 
the same way as do the veins. 

The nerve system is very intricate. But 
the general idea of its structure and functions 
that has been given is sufficient for our pur¬ 
poses. There are some things about it that it 
would be impossible to explain. The whole 
action of the nervous system is one of the great 
problems that science has not yet been able to 


A STUDY OF THE NERVOUS SYSTEM 391 


solve. We know where the nerves are, we know 
their functions, but by what means and by what 
power they perform them yet remain unrevealed. 

There are certain special nerves, with certain 
special functions, called senses, which will be 
described in the following chapter. 

QUESTIONS TO HELP THE PUPIL 

1. May injury to the spine cause paralysis? why? 
2. How can you tell in a case of paralysis whether the 
brain or the spine is injured? 3. What causes infantile 
paralysis? Has a remedy been discovered? 4. What is 
curvature of the spine? How is it caused? 5. What 
disease sometimes develops when the spine is injured? 

6. What kind of play should children be cautioned against ? 

7. What games are to be preferred to football playing? 

8. Describe the appearance of the brain. 9. Where is 
it and how is it protected? 10. How is the skull formed? 

11. Are the bones of the head in children firmly united ? 

12. What is the varying size of the brain in different per¬ 
sons thought to indicate ? Is this always true ? 13. What 

is the use of the brain? 14. Of how many parts does it 
consist? 15. Where is the spinal cord located? 16. 
Describe the spinal column, telling of its structure and 
naming its parts. 17. What activities are thought to be 
controlled by the spinal cord? 18. What is the work of 
the nerves? 19. Is it known how the nerves carry the 
sensation to the spine and the brain? 20. Tell what 
happens in the nerves when your finger touches an object 
hot enough to bum. 21. Are sensations transmitted as 
rapidly through the nerves in children as in grown per¬ 
sons? in animals? 22. How does the speed compare with 
that of electricity through a copper wire? 23.. Define and 
describe a voluntary movement; an involuntary move¬ 
ment. 24. Name some involuntary or automatic move¬ 
ments. 25. What are sensory nerves? motor nerves? 
26. May widely separate nerves take part in a sensory 
and motor process? Give an illustration. 


XXXII. A Study of the Senses 


THE SENSE OF SIGHT 

What is the optic nerve? The optic nerve, or 
the nerve that makes it possible for us to see, 
is one of the most important of the special 
nerves. The eye, the organ of vision, is one 
of the wonders of the human body. It is 
shaped much like a big marble, and is filled 
with materials that permit light to pass through 
as light passes through a window pane. You 
have seen how a mag¬ 
nifying glass seems to 
enlarge an object seen 
through it. Such a 
glass is called a lens. 
The eye is provided 
with a lens made of a 
transparent substance 
held in a transparent 
membrane. This lens 
serves to concentrate 
the rays of light on a 

Under surface of brain showing black membrane, 
the optic nerve 

a,a, optic nerve; b,b, cerebrum; called the retina, at 

c,c, olfactory nerve bulbs; d,d, cere- , 1 1 r , 1 

beiium; e, spinal cord the back ot the eye. 

In the retina are distributed the nerves of vision. 
The sensations produced on these nerves in the 



392 


A STUDY OF THE SENSES 


393 


retina by the rays of light that pass through the 
lens of the eye are carried along the nerve called 



the optic nerve to that part of the brain to which 
the nerve is connected. There are registered 
the images produced on the retina. 

If you look closely at the eye of your friend 
you will see in it' the image of yourself. But 
that image is merely the reflection of yourself 
as from a mirror. The image your friend 
receives of you lies on the black curtain or 
retina at the back of the eye. But if you could 
see the retina you would see nothing but a 
black surface. There is no difference in prin¬ 
ciple between the way the eye is made and the 
way a camera is made. Both have a lens in 
front through which the light is concentrated 
on a black sensitive curtain at the back. 

The image of an object, registered in the brain, 
is the same for all normal eyes. Looking at a 
picture you will see just what your neighbor sees, 
unless your eye or your neighbor’s is defective. 














394 


HEALTH READER 


What are the chief parts of the eye ? The eye is 

an almost perfectly round ball from three fourths 
of an inch to an inch in diameter, so placed in 

a depression in 
the bones of the 
face and skull 
as to leave ex¬ 
posed only a 
portion of its 
surface. 

The white 
outer coating 
of the eyeball, 
Diagram of the eye a portion of 

which is visible between the eyelids, is known 
as the sclerotic coat, from a Greek word meaning 
“hard.” This coat is opaque , that is, light can¬ 
not pass through it, except in the portion over 
the round colored spot in the front part of the 
eye. That portion of the outer coat is called 
the cornea. The cornea projects from the sur¬ 
face of the eyeball so that it looks as though 
iff were a part of a smaller sphere lying within 
and slightly projecting from a larger sphere. 

The eye is filled with a transparent jelly- 
like substance called vitreous humor. Vitreous 
means “resembling glass.” The vitreous sub¬ 
stance in the eye, however, resembles glass only 
in its quality of transparency. Toward the 



A STUDY OF THE SENSES 


395 


front, just behind the cornea, is a transparent 
semi-solid substance known as the crystalline 
lens. It is made up of various layers or cells, 
which may be compared to the layers of an 
onion so far as structure is concerned. It is 
through this lens that the rays of light pass to 
the sensitive inside coating of the eye, which 
has already been spoken of as the retina. 

The retina is a black mem¬ 
brane, over which the numberless 
filaments of the nerve of vision, 
the optic nerve, are distributed. 

Back of the cornea 'and in front 
of the lens is a colored curtain 
called the iris. In the center of | 
the iris is a circular opening 
the size of which is adjustable 
according to the intensity of 
the light. This opening is called 
the pupil. When the light is 
strong the iris contracts so that 
the opening is very small; in the 
dark the iris expands so that the 
opening is very large. The iris 
corresponds to the diaphragm of 
a camera. If the light is very 
intense the diaphragm of the 
camera is set so that the hole through which 
the light enters is very small. If the light is 



Section of the eye 
showing lens 
a, lens adjusted for 
far objects; b, lens 
adjusted for near ob¬ 
jects; c, c, ciliary proc¬ 
ess; d, d, suspensory 
ligament; e, e, pos¬ 
terior chamber; /, /, 
iris; g, cornea; h, an¬ 
terior chamber 



396 


HEALTH READER 


less intense the hole in the diaphragm of the 
camera is made larger. In the iris the adjust¬ 
ment of the opening is accomplished by means 
of small muscles which act automatically. 
The opening in the iris, whether large or small, 
always remains circular. 

What causes the color of the eye? The color of 
the eye is due to the coloring pigment in this 
movable iris. In all eyes the pupil appears to 
be nothing but a black spot. What you see 
there is probably a part of the retina. But 
what we call the “ color ” of the eye is determined 
by the color of the iris. The color of the iris 
is never black, but varies from deep brown 
through all the different shades to light gray 
or blue. 

Are there other lenses in the eye besides the 
crystalline lens? The fluid in the front part of 
the eye, between the crystalline lens and the 
cornea, forms another lens. This fluid is called 
aqueous , meaning watery, because in its density 
it does not differ largely from water. The 
vitreous humor, which we have learned fills the 
greater part of the cavity of the eye behind the 
crystalline lens, also forms a lens. 

What is blindness ? Blindness is the incapability 
of the optic nerve to receive or transmit sensa¬ 
tions of light. It may sometimes be the result of 
some defect in the optic nerve or it may be caused 


A STUDY OF THE SENSES 


397 


by some defect in the eye itself. If there is a 
defect in the lens, light cannot be transmitted 
to or concentrated properly on the retina. If 
there is a defect in the retina, the nerves cannot 
receive the impression or transmit it to the 
optic nerve. On the other hand the brain cells 
that receive the impression may be diseased. 
Thus blindness may result from defects in the 
make-up of the organ itself, from defects in the 
transmitting apparatus of'the optic nerve, or 
from defective brain celis. When we say that 
an eye is “put out,” as the saying is, it does not 
necessarily mean that the eye is removed from 
its socket but that it is so injured that it no 
longer perceives sensations of light. The de¬ 
struction of the lenses of the eye by accident, or 
the hardening of these lenses because of old age 
or some other reason, may result in blindness. 

What is the disease known as cataract? The 
word “cataract” usually makes us think of 
water falling over a steep cliff. But when we 
use this word in speaking of the eye we mean 
the hardening and whitening of the crystalline 
lens. 

When this lens becomes hardened and whit¬ 
ened so the light can no longer penetrate to the 
retina, it may be removed and the remaining 
lenses used in its place. The vision will be 
restored, but it will not be so perfect as before. 


39§ 


HEALTH READER 


What is nearsightedness ? The crystalline lens 
of the eye may be so formed that the rays 

of light from 
an object are 
brought to¬ 
gether at a 
point that 
falls short of 
the retina, 
that is, some¬ 
where be¬ 
tween the 
lens and the 
retina. In 
some persons 
also the eye¬ 
ball may be 
too long from 



Short-sight 


Diagrams of eye showing normal, far, 
and short sight 


front to back. In such cases the rays of light 
from objects come together at a point that also 
falls short of the retina. In both these cases 
the person is said to be near-sighted. 

What is farsightedness ? Farsightedness re¬ 
sults when the lens is so formed that it does not 
bring the rays of light to a point quickly enough 
or when the eyeball is short from front to back. 
A farsighted person can see better if the object 
is at a greater distance. In perfectly normal 
eyes the lenses are so adjusted that the person 












A'STUDY OF THE SENSES 


399 


can read print very well at a normal distance 
of fifteen or twenty inches and also can see ob¬ 
jects at a distance of one hundred feet, or half 
a mile, or mountains ten miles or even farther. 

How may nearsightedness and farsightedness be 
corrected? With a knowledge of the causes of 
nearsightedness and farsightedness, the man who 
has the skill can so grind lenses of glass as to 
correct the faults in the natural lenses of the 
eye. For nearsightedness a lens of one form 
and thickness is ground, and for farsightedness, 
a lens of another form and thickness. In this 
way opticians are able to correct imperfect 
vision due to faults in the structure of the eye. 

What is astigmatism ? In some eyes the 
cornea may not be curved correctly; that is, 
instead of forming an evenly curved surface 
there may be flat places on it. Such a defect 
may also be found in the crystalline lens. The 
rays of light that pass through such an uneven 
surface cannot come together at the same point 
on the retina. The result is that some parts 
of the image are clear and other parts blurred. 
This trouble is called astigmatism. 

How may astigmatism be corrected? In cases 
of astigmatism the skilled optician provides 
glasses in which the form of the lens corrects 
the defects in the cornea or the lens and causes 
the rays of light to come together to a point. 


400 


HEALTH READER 


What is meant by the term “cross-eyed”? The 

movement of the eyes in their sockets is con¬ 
trolled by a number of small muscles. The 
eye can be moved to the right or left, up or 
down, or in a circle, in order that we may look 
at objects in different places without turning 
our heads. In normal eyes the movements of 
the muscles are coordinated; that is, they work 
so as to move both eyes at the same time in 
exactly the same way. You cannot move one 
eye without moving the other, though you can 
move one finger without moving another. 

Eyes are said to be crossed when the lines of 
vision are not parallel, that is, when they do 
not look in the same direction at the same time. 
They may either look toward each other, so 
that the lines of vision cross, or they may be 
turned outward, though such cases are rare. 

How may cross-eye be corrected? Cross-eye 
cannot be corrected by any kind of mechanical 
contrivance. If there is only a slight crossing 
it may be helped by a skillful adjustment of 
eye glasses. In serious cases, there are only 
two plans to follow—either to leave the task 
to nature, which sometimes corrects this trouble, 
or to secure the services of a surgeon. An eye 
is turned too far in one direction or the other 
because one set of muscles is stronger than the 
other. For instance, the muscle that pulls the 


A STUDY OF THE SENSES 


401 


eye toward the nose must not be stronger or 
weaker than the muscle that pulls the eye in 
the opposite direction. Thus both eyes can 
look straight forward or they can turn an 
eqpal distance to the left or to the right. If 
the muscle that pulls the eye toward the nose 
should become stronger than the muscle that 
pulls outward, the eye would be turned in. In 
such cases the skillful surgeon can cut some of 
the filaments of the muscle that is too strong. 

Crossing of eyes is often due to eye strain 
which arises from the intense effort to compen¬ 
sate defects in the seeing apparatus. In such 
cases glasses correcting the defects in the lens 
of the eye will also often correct the crossing. 

What is meant by “sore eyes”? In addition to 
the disorders to which attention has already 
been called, the eye may be affected by various 
kinds of inflammation which attack the mem¬ 
branes surrounding it. These inflammations 
are often of an infectious character. The eye 
inflamed by overuse may cause the blood ves¬ 
sels of the eye to carry to it a larger amount of 
blood than is needed. These unnecessary par¬ 
ticles of blood sometimes remain in the capil¬ 
laries, thus producing what we call “bloodshot” 
eyes. Overstraining, or using the eye in too 
brilliant a light, will cause similar troubles. 

When reading, one should never face the 


402 


HEALTH READER 


light. It should come obliquely from behind, 
over one or the other shoulder of the reader as 
is most convenient. Using the eyes in a very 
bright white light may be injurious. The green 
light produced from tubes filled with mercury 
vapor or by the use of green shades is less 
harmful to the eyes than the white or brilliant 
light of the electric arc or incandescent lamp, 
or of the gas jet surrounded with a mantel. 

Abraham Lincoln used the light from a burn¬ 
ing log in the fireplace. The light given off by 
such a flame is yellowish and is not very brilliant, 
so probably it did not hurt his eyes. We do not 
read by that kind of light now, and we are not 
so careful as we should be to shade our lights 
or to sit in such a position as to avoid eye strain. 

Has the eye any relation to health ? The eye is 
very important in its relation to health. Many 
forms of headache are due to defects in the eye. 
When these defects are remedied by the use 
of glasses ground correctly, the headache dis¬ 
appears and the general health is improved. 

Has light any relation to health? Not only 
is light necessary in order that our eyes may see, 
but light is also of the highest importance to 
good health. Without light, normal growth is 
impossible. If you put a potato in moist earth 
in a dark cellar it will sprout, but the plant will 
never reach mature growth and will have no 



A STUDY OF THE SENSES 


403 


color. If you keep a child in a dark room he 
may grow, but he will be thin, white, and 
imperfectly developed. 

But as a rule the beginning of all growth 
requires an absence of light. A seed will start 
to grow much more readily when covered with 
earth or if it is kept in the dark than if exposed 
to the light of the sun. All bacteria are vege¬ 
tables of a primitive character, and hence, like 
the seed of a vegetable, which is its primitive 
stage, the germs grow best in the dark. So 
light is of the highest importance to us, not only 
because it helps us to see and to grow, but also 
because of its ability to kill germs that threaten 
our health. There is no better germicide , or 
germ killer, than bright sunlight. 

Light is as necessary to our existence as heat. 
Fortunately, one usually accompanies the other. 
The sun is the origin, so far as our world is 
concerned, of both light and heat. Light is 
indispensable to our health, and to it we owe 
most of the joys of life. 

What is the value of light in convalescence? The 
convalescent—the person who is on the way 
from sickness to health—should be kept as 
much as possible in the sunlight. Unfortunately 
there are some diseases in which light is injuri¬ 
ous, as, for instance, in diseases of the eye or 
diseases which affect the eye. Measles makes 


404 


HEALTH READER 


the eye sensitive, and the boy or girl suffering 
from this disease must be kept in the dark. 
The person suffering from inflammation of the 
membranes bf the eye must also be kept in the 
dark. But if a person has tuberculosis, or is 
recovering from some ordinary illness, he should 
remain constantly in a well-lighted as well as a 
well-ventilated place. 

Light is very effective in preventing the loss 
of hair. The sun’s rays tend to kill germs that 
destroy the hair. If we go bareheaded as much 
as we can, and let the sun shine on our heads, 
there will be fewer bald heads in the future than 
there are at the present day. Tight hats cut 
off the blood supply from the scalp and thus 
promote baldness. 

THE SENSE OF SMELL 

What is the olfactory nerve ? The sense of smell 
is communicated to the brain through two 
nerves, the filaments of which are distributed 
in the shape of a fan principally on both sides 
of the membrane separating the nostrils. These 
nerves are called the olfactory nerves. They 
connect directly with two bulbs in the base of 
the brain, called the olfactory bulbs, and these 
in turn are connected with that particular part 
of the brain which seems to preside over the 
sense of smell. 


A STUDY OF THE SENSES 


405 


How do the nerves carry the sensation of smell ? 

Just how the olfactory nerves receive and trans¬ 
mit the sensation of smell is not understood any 
better than how any nerve carries any kind of 
sensation. All we know is that it is their func¬ 
tion to do so. Substances that have an odor 



and therefore affect 
the sense of smell 
are believed to give 
off very minute 
particles that carry 
the odor. These 
particles of matter 
strike against the 
filaments of the 
nerves in the nasal 


passages and excite Section of nose showing olfactory nerve 


them in such a way 


a, olfactory tract; b, olfactory bulb; 
c, olfactory nerves; d, nasal cavity; 
e, roof of mouth 


as to produce a cer- * roof of mouth 
tain sensation. This sensation is transmitted 
through the olfactory nerves to the olfactory 
bulbs and then to the brain. The sensation 
may be one of two general kinds, the agreeable 
or the disagreeable. The odors that produce 
an agreeable sensation do not excite the nerve 
filaments in the same way as do those that pro¬ 
duce a disagreeable sensation. 

Does the sense of smell in various animals differ 
in keenness? Very much so. Some animals 








406 


HEALTH READER 


have, so keen a sense of smell that it is almost 
unbelievable. By means of this wonderfully 



Bloodhounds scenting the trail 


developed sense some dogs are able to trace 
the course which an animal or a man has taken. 
A dog and a human being are at almost opposite 
extremes in regard to the sense of smell. In 
man it is at a decidedly low stage of develop¬ 
ment, while in the dog it is very highly devel¬ 
oped. The hound can follow a trail swiftly and 
unerringly, so quickly are his olfactory nerves 
affected by the slightest odor. Bloodhounds 
can distinguish the odor of one individual from 
that of another, and can thus track a certain 
person on trails over which many others have 
passed. The keenness of the sense of smell in 
such cases seems almost beyond comprehension. 







A STUDY OF THE SENSES 


407 


Why do colds diminish the keenness of scent? 

It is easy to understand how a cold affecting 
the nasal passages can diminish the sense of 
smell and even stop it entirely. The olfactory 
nerve filaments are placed in the mucous mem¬ 
brane of the nose in such a way that the minute 
particles carrying the odor may come in contact 
with them. A cold in the nose causes inflam¬ 
mation, a temporary thickening of the mucous 
membrane, and the excretion of large quantities 
of mucus which cover the membrane and thus 
prevent odors from affecting the nerve filaments. 
When the inflammation reaches a certain de¬ 
gree, the sense of smell is for a time entirely lost. 

Are there differences in the keenness of scent 
among different persons? There is just as much 
difference in the development of the sense of 
smell in different persons as there is in the devel¬ 
opment of other senses. In some people the 
sense of smell is very keen. There are many 
persons who cultivate it, for it is as capable of 
cultivation as any other sense. In those whose 
profession it is to distinguish between various 
objects by the sense of smell, this sense becomes 
very highly developed. The expert distin¬ 
guishes the various grades of teas, coffees, 
alcoholic beverages, and other products largely 
by the sense of smell. Some persons also are 
naturally endowed with a keener sense of smell 


408 


HEALTH READER 


than others, and so are much more capable of 
telling the difference between odors. 

Does the sense of smell have any relation to 
health ? The sense of smell has important rela¬ 
tions to health. Most foods have an agreeable 
odor when they are fresh and suitable for eating. 
If they are decayed or unwholesome the agree¬ 
able odor is changed to a disagreeable one. 
Thus the sense of smell tells us what is good 
for us to eat and what is bad. Though the odor 
of a fresh egg is not particularly agreeable, still 
it is not offensive. But if the egg is bad our 
sense of smell tells us immediately that it is 
unfit for food. In the same way harmful gases 
mingled with the atmosphere are revealed by 
their odor and we are thus placed on our guard. 
Thus we see that the sense of smell aids us in 
many important ways in keeping our health. 

What is the relation of the sense of smell to the 
flavor of our foods and drinks? The term “fla¬ 
vor” is often used incorrectly. Flavor is not 
taste alone, nor is it odor alone. The flavor 
of a food is its taste and smell combined. 
Sugar, for instance, tastes very sweet, but as 
it does not produce a sense of smell, sugar has 
no flavor. In order to have a flavor a substance 
must have the properties which excite, at the 
same time, both the nerve of taste and the nerve 
of smell. 


A STUDY OF THE SENSES 


409 


THE SENSE OF TASTE 

What is the nerve of taste? Just as the 
thought of an odor brings the thought of the 
nose to our minds, so the idea of taste brings 
the thought of the tongue. The tongue has 
more than one function. It is especially useful 
in speaking. Without the tongue, the sounds 
made by means of the vocal cords would not be 
articulate; that is, they could not be formed into 
definite sounds and words. Another important 
function of the tongue is to assist in chewing and 
in carrying food 
into the back part 
of the mouth, 
where it is seized 
by the muscles of 
the throat and 
carried into the 
esophagus. All 
these functions of 
the tongue are im¬ 
portant and useful. 

In our present dis¬ 
cussion we shall re¬ 
gard the tongue 
particularly as the 
organ of taste. 

The tongue is covered with numerous small 
projections called papillae , which form a part 



The tongue 


14 


4io 


HEALTH READER 



Section of papillae valata of the human 
tongue, showing taste buds 
a, papilla; b, b, taste buds 


of the mucous membrane covering the tongue. 
The papillae, when magnified, appear to be 

projections of 
considerable size, 
around each of 
which is a de¬ 
pression or fur¬ 
row. The nerve 
of taste, called 
the gustatory 
nerve, divides 
into minute 
threads or fila¬ 
ments that pass 
into the papillae and emerge in the depressions 
around the papillae in what are called taste buds. 
The nerve of taste does not appear to communi¬ 
cate directly with the brain, but reaches it in 
connection with other nerves, and especially 
with the one known as the fifth nerve. That 
certain portions of the brain have charge almost 
entirely of the sense of taste is evident from the 
fact that injuries to certain connections of the 
fifth nerve in the brain destroy or at least 
cause injury to the sense of taste. 

How many kinds of taste do we possess? The 
sensations produced in the nerve of smell have 
been classified broadly as agreeable and dis¬ 
agreeable. A more detailed classification can 


A STUDY OF THE SENSES 


411 

be made of the various sensations of taste. 
The sense of sweetness is usually a highly 
developed sensation. There is also a distinct 
sensation of bitterness. But the sensation we 
call sour, or acid, is entirely different from these 
two. Probably a sour or acid taste is more 
nearly the opposite of a sweet taste than the 
taste we call bitter. Forming another distinct 
class of taste sensations are those caused by 
common salt and similar substances. This is 
called the saline or salt taste. As we have 
already learned, the sense of taste, together 
with the sense of smell, has the function of 
perceiving flavor. 

These separate sensations may be regarded 
as the principal kinds of taste sensations. But 
when mingled they produce numberless varia¬ 
tions and combinations in which all these kinds 
take part. 

What is the theory of transmission of the sense 
of taste? We find that the transmission to the 
brain of all our knowledge of the world around 
us depends on actual physical contact of sub¬ 
stances with the various nerves. This is also 
true of the transmission of taste. The sub¬ 
stances which produce the sensation of taste 
must come into direct contact with the nerve 
filaments distributed at or near the surface of 
the mucous membrane in the depressions around 


412 


HEALTH READER 


the papillae. We cannot conceive of any other 
way in which the sensation of taste can be 
produced. 

It is probable that the nerves of taste in 
various' parts of the tongue have different 
degrees of sensibility, and even perceive different 
kinds of taste according to their location. The 
expert taster can distinguish the difference 
between the taste of a substance when held 
near the tip of the tongue and the taste of the 
same substance when held farther back toward 
the throat. It is reasonable to suppose that 
the anterior (front) filaments are less delicate 
than the posterior (back) filaments, since they 
come into contact with the food when it is in a 
more or less solid state. It may be that the 
differences in the taste sense in different parts of 
the tongue are not because of any particular 
differences in the nerves, but because some 
taste nerves are less sensitive than others. It 
is generally believed that a bitter taste is most 
readily perceived near the back of the tongue. 
It is even claimed that at the tip of the tongue 
a bitter taste cannot be perceived at all. 

In what condition must a material be in order to 
produce the sensation of taste? Substances do 
not affect the sense of taste unless they are 
wholly or partly in a state of solution. If the 
surface of the tongue is perfectly dry and the 


A STUDY OF THE SENSES 


4i3 


substance placed on it is perfectly dry, no 
sensation of taste is produced. But if the sub¬ 
stance is either in solution or else so finely cut 
up that it has the properties of a liquid, the 
nerve of taste is immediately affected and the 
sensation is transmitted to the brain. • 

The taste of a hard substance develops quite 
rapidly with chewing, and a much stronger 
sensation of taste is produced than when the 
food is in coarse fragments or partly dissolved. 
Thus we are able to judge by the sense of taste 
when our food has been chewed well enough 
and is ready to be swallowed. 

What is the effect of temperature on the sensation 
of taste? If the temperature of food substances 
is widely different from the normal temperature 
of the mouth, the sense of taste may be very 
seriously affected. If a substance is extremely 
cold it produces a sensation of cold, which 
itself tends to deaden the sense of taste. On 
the other hand, if a substance is very hot i\ 
produces such a painful sensation as to check 
all sensation of taste. Thus if we put an exceed¬ 
ingly cold substance or an exceedingly hot sub¬ 
stance info our mouths we lose the sensation 
of taste. It may be that the nerve of taste is 
active, but the sensation of taste is so obscured 
by the stronger sensation of heat or cold that 
the substance appears to lose all trace of taste. 


4i4 


HEALTH READER 


We would expect the activity of the nerve 
of taste to be at its best when the temperature 
of the substance is the same as the temperature 
of the mouth itself, or about ninety-eight and 
a half degrees. As a matter of fact, however, 
experience has shown that a somewhat lower 
temperature is better. We can best distinguish 
slight differences in taste at a temperature of 
from sixty-five to seventy-five degrees. 

Has the sense of taste any relation to good health? 
The sense of taste has a very important relation 
to health. It is the taste of a substance that to 
a great extent causes the secretion of the fluids 
which digest the food. A good taste tends to 
increase the activity of the glands that secrete 
these fluids. A bad or objectionable taste will 
produce entirely the opposite effect. So it is 
evident that the sense of taste bears a very 
important relation to health. 

What is the effect of temperature on the whole¬ 
someness of foods? The temperature of the 
food we eat has also an influence on health. 
Those who have trained the sense of taste and 
the sense of smell to perceive very delicate 
flavors, are extremely particular in regard to 
the temperature of their food and drink. In 
tasting red wine an expert taster requires the 
temperature of the wine to be about seventy- 
five degrees. On the other hand, most persons 


A STUDY OF THE SENSES 


4i5 


who have no knowledge of the nature of the 
sense of taste desire their foods served at a very 
low temperature. This is true especially in the 
United States, where most families, even those 
in moderate circumstances, are able to keep ice 
during the summer. 

There is a perfect mania, particularly in 
summer, for ice-cold drinks — water, lemonade, 
buttermilk, and other beverages. We also have 
a great desire for ices and frozen dainties of all 
kinds and of all descriptions. But the laws of 
nature are very seriously abused when we take 
foods at so low a temperature. We are equally 
fond, especially in winter, of certain very hot 
drinks, thus going to the other extreme. In 
both cases the sense of taste is impaired by the 
extreme temperatures, which is more or less 
injurious to health. 

The lesson to be learned is that we should 
not eat foods above or below certain tempera¬ 
tures—cold foods not below fifty degrees, and 
warm foods not much above the temperature 
of the body. If we observe these precautions 
we can perhaps save ourselves from serious 
harm. 

We should avoid the copious use of ice-cold 
drinks during the hot days of summer. Water 
is perfectly palatable at a temperature of from 
fifty to sixty degrees, while ice water has 


416 


HEALTH READER 


practically no taste whatever. Thus when we 
go to extremes in temperature in our daily 
diet we not only lose a great deal of the pleasure 
of eating, but we injure our health besides. 

THE SENSE OF HEARING 

What is the auditory nerve ? The auditory or 
hearing nerve is another path over which the 
knowledge of the outer world reaches the brain. 
The nerve of hearing transmits sounds to the 
brain. The external ear needs no description. 
Everybody knows what it looks like. The ex¬ 
ternal ear has little to do with the sense of hear¬ 
ing. The real ear is inside the head in the 

middle of a very 
hard bone. The 
passage leading to 
the inner ear is 
closed a short dis¬ 
tance in by a mem¬ 
brane which may 
be compared to the 
head of a drum. 
This membrane, 
stretched tight 
across the opening, 
is called the tym¬ 
panum , a Latin word meaning ‘‘ drum.’’ Back of 
the tympanum is a cavity called the middle ear . 



The drum and hones of the ear 

a, incus (anvil); b, malleus (hammer); 
c, handle of malleus; d, sensor tympani; 
e, Eustachian tube;/, tympanic membrane; 
g, stapes (stirrup) 


A STUDY OF THE SENSES 


417 


The middle ear is connected with the throat 
and mouth by a tube called after the name of 
its discoverer, the Eustachian tube. This tube 
has a double purpose. Through it the middle 
ear may be kept properly moistened and lubri¬ 
cated, and at the same time kept full of air. 
The pressure of air on the inside of the drum 
is thus the same as the pressure on the outside. 
Should the Eustachian tube become clogged up, 
as sometimes happens in case of colds or sore 
throat, the air would be shut off from the middle 
ear. Then the pressure of air on the outside 
of the drum pushes it inward and the hearing is 
affected. 

The sensation of sound is produced by the 
impact of vibrations in the air against the ear 
drum. Whenever a noise is made or a word is 
spoken vibrations are set in motion in the air 
which travel rapidly in all directions. 

If you pass by a pond in calm weather, you 
will see that the surface is perfectly smooth. 
If you throw a pebble into the pond, ring-like 
waves of water will pass rapidly one after 
another from the point where the pebble struck 
the surface of the water, and proceed in circles 
at the same rate of speed in all directions. 
Something of this kind happens in the air 
when a word is spoken. As a word emerges 
from the lips it strikes the external air and sets 


4i8 


HEALTH READER 


up a wave motion which travels in every 
direction. These waves strike every object 
within a certain radius and reach the ear drum 
of any person who happens to be within hear¬ 
ing distance. The air waves start a vibration in 
this membrane corresponding in character and 
strength to their character and strength. 

In what particular way is sound transmitted from 
the ear drum to the brain? Immediately within 
the ear drum is a series of three small bones. 
The first touches the ear drum and rests on the 
second, and the second rests on the third. The 
third bone connects with what is called the 
inner ear where are located the nerves of hearing. 
It is through these three little bones that the 
sound is started on its journey to the brain. 
They are provided with muscle-like cords by 
means of which they can be tightened or 
loosened, in much the same way that a violin 
string is tightened or loosened by means of a 
peg. Thus the sensitiveness of the bones, that 
is, their power of transmitting sound, may be 
increased or diminished by the action of the 
muscles attached to them. 

These cords adapt the apparatus of the ear 
to the special sound it is trying to transmit. 
The auditory nerve terminates in the inner 
ear in hair-like filaments or cells. These receive 
the vibrations transmitted by the small bones 


A STUDY OF THE SENSES 


419 


in contact with the tympanum, or ear drum, 
and send them inward toward the brain. These 
numerous hair-like cells are arranged in quite 
regular rows and may be compared to the keys 
of an organ or a piano, though there are more 
than two rows. In fact, there is a very large, 
number of these organ keys; it is estimated that 
there are from twelve to twenty thousand. 
Thus it is evident that the complexity of the 
ear organ is far greater than that of the church 
organ. 

What is a phonograph? The word “phono¬ 
graph” means sound writing. If you attach 
a feather to a membrane stretched like the 
head of a drum, and allow the point of the 
feather to rest on a piece of smoked paper or 
glass while you speak a series of words, and at 
the same time move the smoked plate, the 
feather will write in waving lines. This proves 
that the words you spoke caused a series of 
vibrations in the membrane. If instead of the 
feather you use a delicate needle with a sharp 
point capable of writing on wax, you have the 
basis of the phonograph. 

In the phonograph you speak into a tube 
leading to the membrane. That membrane 
has a pen attached to it which rests upon a 
moving wax cylinder or plate. The waves of 
sound transmitted to the membrane cause the 


420 


HEALTH READER 


pen to write a waving line in the wax corre¬ 
sponding to the strength and character of the 
sound of the words you speak. In much the 
same way the vibrations in the drum of the ear 
are recorded, not on smoked glass nor on wax 
but in the brain itself. 

What relation has the ear to health? The 
power to distinguish sound is one of the impor¬ 
tant means we have of knowing what is going 
on around us. For this reason it is evident that 
the sense of sound is of great importance to our 
welfare. The sense of sound often warns us of 
physical danger, so that we are able to avoid 
accidents or injuries which otherwise would 
befall us. 

The ear is subject to certain diseases more or 
less injurious to our general health. Back of 
the ear is a portion of the skull, called the 
mastoid bone, which is spongy in character. 
In certain disorders of the ear this bone some¬ 
times becomes affected, causing great pain and 
danger. The ear itself, with its various organs, 
is often subject'to strain or inflammation. This 
causes earache, a troublesome disease. The 
tube leading from the ear to the throat, called 
the Eustachian tube, may also become infected 
as the result of colds or inflammations, and may 
even become clogged, a most dangerous con¬ 
dition, 


A STUDY OF THE SENSES 


421 


The sense of hearing gives us many of the 
pleasures of life. The conversation of friends, 
the notes of beautiful music, the song of the 
birds in the trees, the chirp of the cricket, the 
sound of running waters, all are pleasing and 
give us a feeling of happiness and contentment. 
In this way the sense of hearing helps to keep 
us in good health by making us happy. 

Are we able to locate the sources of sound? 
When we see an object we know exactly its 
location and can judge approximately its dis¬ 
tance and its size. When we hear a sound we 
are not able to tell exactly where it came from. 
The source of a sound can to a certain extent 
be located, but with nothing like the accuracy 
with which a visible object can be located. 
People differ greatly in their ability to sense 
the source of sounds. 

How fast does sound travel? In the air sound 
travels about 1,100 feet per second; in solid 
bodies it travels much faster. It was recorded 
that the cannonading at Fort Donelson on the 
14th of February, 1862, could be heard nearly 
200 miles away. Subsequent investigation 
showed that the sound had traveled through a 
layer of limestone. Sound may be carried much 
farther through solid bodies than through the 
air. You see the flash of the lightning some 
time before you hear the thunder. 


422 


HEALTH READER , 


THE SENSE OF TOUCH 

What is meant by the sense of touch or feeling ? 

If we close our eyes and place our hands on an 
object, a distinct sensation is experienced. The 
nerves that transmit this sensation to our brains 
are the nerves of touch or feeling. The moment 
our hands come in contact with an object we 
can determine, without looking at it, whether 
it is hard or soft, rough or smooth, round or 
angular, and whether it is hot or cold. Thus 
it is clear that the sense of touch or feeling is a 
very complicated sense into which enter a great 
many factors. 

Some of the things that can be determined 
by the sense of touch, can also be determined 
by the sense of sight. For instance, the shape 
of an object, and whether it is rough or smooth, 
can easily be determined by looking at it as well 
as by feeling it. On the other hand, there are 
certain characteristics of an object revealed by 
the sense of sight which the touch cannot reveal 
—for instance, the color. 

Of all the senses, that of touch may be 
regarded as the most universal; that is, it gives 
us more information and of a more varied char¬ 
acter than we can gain from any other set of 
nerves. But it cannot be regarded as the most 
desirable or pleasurable, though without doubt 
it is the most useful. We may lose the sense of 


A STUDY OF THE SENSES 


423 


sight, of hearing, of taste, of smell, and still 
exist tolerably well, but should we lose also 
the sense of touch we should be utterly help¬ 
less. The case of Helen Keller is a remarkable 
instance of the possibility of obtaining a fine 
education through the sense of touch alone. 
Through illness she lost the senses of sight and 
hearing at a very early age, yet she has become 
a cultured and highly educated woman. 

How is the sense of touch or feeling exerted? 
The nerves which carry the sensation of touch 
are located mostly in the skin. The skin has 
already been described as a very useful and 
necessary covering of the body. It can now 
also be described as the chief organ of touch. 
The skin is by no means the only part of the 
body that has nerves of touch. Such nerves 
are found also in the tongue and in the muscles 
and to a certain extent in the internal organs 
of the body, though in the latter they are greatly 
modified. 

The best authorities declare that the various 
functions of the sense of touch are not carried 
on by the same nerve filaments. In other words, 
the sensation by means of which we get the 
outlines of a body and determine whether it is 
rough or smooth is carried by one kind of nerve 
filament, while the sensations of cold, of heat, 
and of pain are each carried by other kinds of 


424 


HEALTH READER 


nerve filaments. These filaments are probably 
continuous—that is, they pass in bundles from 
the brain through the spinal cord and radiate 
from the spinal cord to all parts of the body, 
where the bundles break up into the separate 
filaments. 

The skin itself is not perfectly smooth, as 
one might suppose, but is covered with numer¬ 
ous small projections or papillae, particularly 
on the scalp and often on the arms and other 
parts of the body. These papillae carry hairs 
which may be regarded as the advance guards 
of the nerves of touch. Anything coming in 
contact with one of these fine hairs is likely to 
stimulate the sense of touch. 

The principal purpose of hair is protection, 
but it also has the secondary property of 
exciting, or tending to excite, the nerves of 
touch. 

The nerves of touch vary in abundance in 
different parts of the body. They are very 
numerous in the hands, the feet, and at the tip 
of the tongue. They are more sparsely dis¬ 
tributed over the skin of the arms, the neck, 
the back, and other portions of the body. 
There are more of these sensory points in the 
fingers and the tongue than in any other part 
of the body. 

The remarkable skill that can be developed 


A STUDY OF THE SENSES 


425 

in the fingers results from the training or edu¬ 
cation of the nerve of touch. For instance, in 
such trades and professions as piano playing, 
billiard playing, watch making, or surgery, the 
sense of touch must be highly developed. 

Are the internal organs supplied with nerves of 
touch or feeling? The nerves of feeling in the 
internal organs are few in comparison with the 
number in the skin. We do not have any 
pleasurable sensations in the internal organs. 
The nerves of feeling there mostly transmit 
feelings of pain. If there is anything wrong in 
the internal organs, the nerves send messages 
of pain to the nerve centers. 

The brain is almost without nerves of sen¬ 
sation. Headaches are usually due to pain in 
the membranes of the brain. In the same way 
when the appendix becomes inflamed we have 
severe pain, but the pain is due largely to the 
membranes which surround the appendix. 

In general we may say that the nerves of 
feeling are distributed through all parts of the 
body, but are especially abundant in the skin 
and the mucous membranes. 

What nerves convey the sensation of pain? 
Almost any nerve will convey a sensation of 
pain. An extreme sensation of any kind be¬ 
comes painful. For instance, a very strong 
odor will cause the olfactory nerve to convey 


426 


HEALTH READER 


a painful sensation. A very strong light causes 
a sensation of pain in the eyes. But the feeling 
of pain, as generally understood, is conveyed 
by filaments of the nerve of touch or feeling. 
These filaments are perhaps the most numerous 
and abundant of all nerve filaments. It is, as 
we have said, difficult to prick the skin without 
touching a nerve conveying a sensation of pain. 
Just what form of vibration, or by what method 
of movement, the sensation of pain is com¬ 
municated to the brain, no one knows. 

Painful sensations are of two general kinds. 
Pressure or puncture of the skin produces one 
of the most common forms of pain. The sensa¬ 
tion of cold is another kind of painful sensation. 
But the nerves that carry the sensation of cold 
are not so numerous as those that carry the 
sensation of other forms of pain. 

What nerves convey pleasurable sensations? 
Agreeable odors and tastes are types of pleasur¬ 
able sensations carried by the special nerves of 
the nose and the tongue. Agreeable music 
produces a pleasurable sensation carried by the 
nerves of the ear. Landscapes and pictures 
and forests and streams produce pleasurable 
sensations carried by the nerves of the eye. 
The nerves of touch in the skin also convey 
pleasurable sensations, due largely to k proper 
degree of warmth or gentleness of pressure on 


A STUDY OF THE SENSES 


427 


the skin. It is very difficult to describe these 
sensations, but we need appeal only to our own 
experience for a further knowledge of them. 

What relation has the sense of touch to our 
health and welfare ? The sense of touch guards • 
our health and comfort in many ways. The 
sensation of cold warns us against temperatures 
that would injure the tissues of the body and 
perhaps cause death. The sensation of heat 
likewise warns us from coming in contact with 
things hot enough to cause injury. The nerves 
of touch tell us the proper temperature in which 
it is comfortable to live. In the winter we 
seek a temperature warm enough to prevent 
discomfort from cold and yet not hot enough 
to threaten health. 

The sense of touch warns us to avoid those 
things which experience teaches are nearly 
always harmful. It also leads us to seek those 
things that add to our comfort and welfare. 
Thus from every point of view the sense of 
touch is highly important in regard to our physi¬ 
cal well-being. 

Are we always able correctly to locate sensations 
of pain ? Though we generally know where we 
have a feeling of pain, sometimes we cannot 
locate it correctly. The pain of a toothache 
sometimes seems to be not in the tooth really 
affected but in some other tooth. A pain in 


428 


HEALTH READER 


the eye or in the back of the head may not 
really be localized there, as we suppose. The 
sensations of pain are reported to the brain, 
but are not always referred by it to the exact 
•place where the trouble lies. 

It is well known that years after persons have 
lost an arm they experience pains that are re¬ 
ferred by the brain to the missing member. 
So a feeling of pain in a certain part of the body 
cannot always be regarded as a certain indica¬ 
tion that the trouble will be found there. 

But as a rule we have little doubt as to where 
the trouble really is. In the case of pain in the 
internal organs we are more likely to be misled 
than in the case of pain in any exterior parts 
where the skin is the organ of sensation. 

How can the delicacy of touch and feeling be 
increased? The sensitiveness of the nerves of 
touch and feeling may be increased by constant 
and judicious use. Education in the ordinary 
sense of the word is the training we get from 
books and teachers in school; in other words, 
it is a cultivation of the brain. To increase the 
delicacy and sensitiveness of the nerves of touch 
by constant and judicious use may be regarded 
as part of the education of the spinal cord. 

The skill which can be acquired by educating 
the nerve of touch is extraordinary. If we 
listen to a master at the piano and compare 


A STUDY OF THE SENSES 


429 


what he does with the slow and clumsy efforts of 
the beginner, we have a good illustration of the 
cultivation of the sense of touch. The skilled 
typist operates 
her machine 
swiftly and ac¬ 
curately without 
looking at the 
keyboard. This 
is true also of 
the skilled pi¬ 
anist. The bil¬ 
liard expert can 
make shots 
which to the un¬ 
skilled player 
appear super¬ 
natural. The 
skilled surgeon can thrust his knife among the 
vital parts of the body, cutting out the offending 
organ, and saving life in a way that seems 
due to almost more than human achievement. 
Such manual skill, due largely to the delicacy 
of the sense of touch, is called technique. 

There is no form of labor that cannot be 
more efficiently performed after cultivating the 
sense of touch. From this we learn the great 
importance in our schools of courses in manual 
training, cooking, and sewing. 



The skilled pianist plays without looking 
at the keyboard 





430 


HEALTH READER 


Can one sense take the place of another? Na¬ 
ture has so endowed us that if one sense is 
impaired or destroyed, the deficiency is made up 
to a certain degree through some other sense. 
The person who is blind may practically see 
with his fingers and ears. He can judge the 
form, contour, and surface of a body by means 
of the nerves of touch. He can learn to walk 
in comparative safety, finding his way by means 
of the sense of hearing. You have no doubt 
seen a blind man walking in the street con¬ 
stantly striking a stick on the pavement in front 
of him. The reflected sound of the tapping 
tells him how near he is to the wall beside 
which he is walking. The pilot of a river boat 

may guide his 
boat safely in 
a fog by con¬ 
stantly blow¬ 
ing the boat’s 
whistle, deter¬ 
mining where 
he is in the 
stream by the 
echo from the 
surrounding 

A blind man walking in the street hills 

The blind man may learn to read by means 
of his fingers. Passing his fingers over raised 














A STUDY OF THE SENSES 


43 i 


letters, he recognizes each letter by the sense 
of touch. By watching the lips of the person 
talking to him, the deaf man is able to under¬ 
stand speech through his eyes. He can tell 
from the movements of a person’s lips just what 
letter or word is being spoken. Thus we see 
that in the person who has lost one sense the 
delicacy and intensity of the remaining senses is 
increased. A blind man may become highly 
educated in any branch of science or letters. In 
fact, a person may lose all his senses except one 
or two and still be able to get some idea of his 
environment. 

According to their comparative importance 
in giving us information about our environment, 
the senses may be arranged in the following 
order: sight, hearing, touch, taste, and smell. 
This seems to be the best arrangement, though 
there may be some difference of opinion, espe¬ 
cially as to which is the more important, hearing 
or touch. 


THE SENSE OF HUNGER 

What is the sense of hunger? We feel the 
sense of hunger chiefly in the stomach. But 
we cannot definitely locate this sensation as 
we can that of a burn or the prick of a needle. 
When we are hungry the general idea seems 
to be that the sensation is in the stomach. In 


432 


HEALTH READER 


this connection we must distinguish between 
starvation and hunger. Starvation is a condi¬ 
tion of the body in which the tissues lack 
nutrition; hunger is a sensation. 

In starvation the victim at first feels a very 
keen sense of hunger. After a while, as the 
starvation progresses the hunger diminishes, 
for the reason that the body has begun to burn 
itself or consume its own tissues. Weight and 
strength decrease, and finally the sense of hunger 
gives way almost entirely to the feeling of weak¬ 
ness and approaching death. 

What relation has the sense of hunger to the 
proper control of our diet ? The feeling of hunger 
does not stop immediately when we put food 
into our stomachs. If we eat rapidly the 
stomach may become quite full and still the 
sensation of hunger remain. For this reason 
we should eat slowly and stop eating before the 
sensation of hunger entirely disappears. 

Every one of you must have noticed that if 
you eat a generous meal hurriedly you still feel 
hungry. But within half an hour after you leave 
the table, although you have eaten nothing more, 
the sense of hunger disappears. From this we 
learn, what it is wise to remember, that hunger 
disappears gradually. We will thus avoid filling 
our stomachs too full with an overabundance of 
food in a useless effort to satisfy hunger quickly. 


A STUDY OF THE SENSES 


433 


THE SENSE OF THIRST 

What is the sense of thirst? Just as the stomach 
is associated with the feeling of hunger, so the 
pharynx , or throat, is associated with the sense 
of thirst. When we are thirsty it does not 
necessarily follow that the system has been 
deprived of water until health is threatened. 
Just as the sense of hunger is felt though there 
is no actual lack of nutrition of the tissues, so 
a feeling of thirst comes though there is no 
dangerous lack of water in the system. If the 
weather is warm and we exercise vigorously, 
more moisture than usual is lost from the body, 
especially by perspiration. Then in some way 
the need of the system for additional moisture 
is localized in the nerves of the throat and 
mouth. The back of the mouth becomes dry 
and the lips parched. 

Thirst is more quickly satisfied than hunger. 
Drinking satisfies the sense of thirst within a 
few moments, long before the water can enter 
the circulation. This also proves that the sense 
of thirst is not due solely to a decreased water 
supply in the tissues of the body. 

QUESTIONS TO HELP THE PUPIL 

i. What is the disease known as cataract? 2. What 
may be done to relieve this? 3. What is nearsight¬ 
edness and what causes it? 4. What is the trouble 
in far-sighted eyes? 5. What is the distance at which 


434 


HEALTH READER 


normal eyes can read print? 6. How may near-sighted 
and far-sighted eyes be corrected? 7. What is astig¬ 
matism and what is the remedy? 8. What are crossed 
eyes? 9. Row may they be corrected? 10. What 
trouble is frequently caused by defects in the eyes? 11. 
From which direction should the light come when a per¬ 
son is reading? 12. What is eye strain and why should 
we be careful to avoid it? 13. Tell how light and good 
health are related; light and germs and bacteria. 14. 
Should a convalescent person remain in the light as much 
as possible? 15. Why is sunlight good for the hair? 

16. Does the sense of smell vary in keenness in animals? 

17. What animal has a highly developed sense of smell? 

18. How do colds affect the sense of smell? why? 

19. Can this sense be developed? 20. How is this sense 
related to good health? 21. What does a bad odor tell 
us about a food? 22. What is a flavor? 23. Has sugar 
a flavor? 24. What is an articulate sound? 25. What 
are the fundamental kinds of taste? 26. Can we per¬ 
ceive more than one kind at a time? 27. Tell about the 
difference in the nerves of taste in different parts of the 
tongue. 28. In what condition must a substance be 
before it can affect these nerves? 29. What is the effect 
of extremely hot or cold substances on the nerves of taste ? 
30. What temperature is suited to the best activity of 
these nerves? 31. What relation has this sense to good 
health? 32. Should we take food and drinks at either 
a very low or a very high temperature? 33. How does 
sound travel in the air? What do the waves of air pro¬ 
duce on the ear drum? 34. To what mechanical device 
can we compare the ear? 35. How does the ear guard 
our health and safety? 36. Is the ear subject to disease? 

37. What pleasures does the sense of hearing give us? 

38. Can you always judge where a sound comes from? 

39. How fast does sound travel? 40. How can you tell 
what an object is without looking at it? 41. What vari¬ 
ous things does the sense of touch tell you about an object? 
What characteristics can we not discover? 42. Can the 
nerves of touch be trained? 43. What tracles and pro¬ 
fessions demand that this sense be very highly trained? 


A STUDY OF THE SENSES 


435 


44. Can one sense be trained to take the place of another? 
Give an instance of this. 45. Can hunger be satisfied by 
eating hurriedly? 46. Can thirst be quickly satisfied? 

47. What is the function of the eye? 48. What is the 
purpose of the lens? the retina? 49. What nerve carries 
the light sensations to the brain? 50. What commonly 
used mechanical device or machine is much like the eye? 

51. Is all of the white outer coat of the eye opaque? 

52. What is the transparent portion called? 53. To what 

may its structure be compared ? 54. Over what part of the 
eye are the nerves of vision distributed ? 55. Describe the 

iris. 56. When is the pupil of the eye small? When 
large? 57. In what part of the structure of the eye is 
the color? Is the iris ever black? 58. What color do 
you see in the pupil? 59. What and where is the aqueous 
fluid ? the vitreous fluid ? 60. How is blindness sometimes 

caused? 61. How are the movements of the eyes con¬ 
trolled? 62. Describe the olfactory nerves. 63. How do 
substances affect the sense of smell? 64. What two gen¬ 
eral kinds of olfactory sensations may there be? 65. 
What are the uses of the tongue? 66. Where are the 
nerves of taste located? 67. What are papillae? 68. 
What name is applied to the nerve of taste? 69. How is 
it connected with the brain? 70. What is the auditory 
nerve? 71. What and where is the tympanum or ear 
drum? 72. Describe the external ear; the internal ear. 
73. What is the Eustachian tube? 74. What happens 
when a sound strikes the ear drum? 75. By what means 
are the vibrations in the ear drum transmitted to the 
nerves? 76. How is the sensitiveness of these small 
bones increased or diminished? 77. How are the audi¬ 
tory nerve filaments arranged? 78. Where are the nerves 
of touch located? 79. Are the sensations of cold, of heat, 
and of pain transmitted by the same nerve filaments? 
80. Where are nerves of touch most abundant? 81. 
Name the two kinds of painful sensations. 82. Do sensa¬ 
tions of pain always tell correctly where the trouble is? 

83. Where does the sense of hunger seem to be located ? 

84. What is the difference between starvation and hunger? 

85. What organ seems to tell us of thirst? 


XXXIII. A Study of Sleep 

What is sleep ? Sleep is a temporary suspen¬ 
sion of the functions of the senses that give us 
our knowledge of the world about us. The 
great purpose of sleep is that the brain, the 
spinal cord, the nerves, and the muscles may 
rest. Though it is possible to rest without 
sleeping and thus partially restore the tired 
brain, nerves, and muscles, the full restoration 
of all the organs of the body to a condition 
suitable for further exertion is best secured 
in sleep. 

How long should we sleep? The answer to 
this question depends upon several conditions. 
In early life a human being needs more sleep 
than he does in later life. The new-born infant 
sleeps nearly all the time. The baby of one 
year will sleep from twelve to fifteen hours a 
day. A child from one and a half to three years 
of age will sleep about twelve *hours a day. 
From three to six years of age a child should 
sleep from nine to twelve hours a day; from 
the age of six to ten, from nine to eleven hours 
a day; and from ten to eighteen, from eight to 
nine hours a day. 

The amount of sleep each person requires 
varies necessarily according to his occupation 
436 


A STUDY OF SLEEP 


437 


and his physical condition. Some persons re¬ 
quire, or at least indulge in, a longer period of 
sleep than others. A man or woman engaged 
in active work requires a minimum of seven 
hours’ sleep, while eight hours would be better. 
The length of time a person sleeps is not the 
only thing to be kept in view; how he sleeps 
is also important. The more peacefully a per¬ 
son sleeps, the fewer the number of hours 
required. On the other hand, if sleep is troubled 
with frequent wakings, twitchings, and move¬ 
ments of the arms and legs, it is less refreshing, 
and more hours are required. 

The man who engages in hard physical labor 
needs more sleep than the one engaged at desk 
work. Brain workers probably need less sleep 
than muscle workers, but they too need peace¬ 
ful and refreshing sleep in order that the brain 
may rest and gather energy for further activities. 

What happens when a person does not get 
enough sleep ? If a person gets too little sleep, 
various disorders may result. These are mani¬ 
fested chiefly through increased sensibility and 
irritability, a diminished power of endurance, 
and decreased strength and vitality. These 
changes, with continued loss of sleep, may even 
make it difficult to sleep at all. 

What is insomnia ? Insomnia , or sleeplessness, 
is the inability to go to sleep when there is 


438 


HEALTH READER 


opportunity to do so. Insomnia is one of the 
most distressing disorders. It is not so trying 
during the day, when the light is bright and we 
are mingling with companions; but it is terribly 
depressing to lie alone in the dark and not be 
able to go to sleep. 

The wear and tear on the nervous system is 
extremely great in such circumstances, and 
when morning comes the sleepless one rises with 
his brain dazed, a general indisposition to engage 
in work or activity of any kind, and usually 
with little or no appetite. 

If sleeplessness becomes chronic, that is, if 
it is continued for a long time, it may develop 
disorders of the brain and bring about neuras¬ 
thenia ,, or nerve troubles. Insomnia may also 
diminish the power of the body to resist infec¬ 
tious or contagious disease. It tends to promote 
an early beginning of the diseases of old age, 
such as hardening of the arteries and diseases 
of the heart and of the kidneys. 

Do people ever sleep too much? There are 
many persons who indulge in a greater amount 
of sleep than they actually require. Too much 
sleep, while not so harmful as too little sleep, 
is nevertheless injurious. A person who sleeps 
too much becomes dull and sluggish both phys¬ 
ically and mentally, and may so weaken the 
power of his body to resist disease as to fall an 


A STUDY OF SLEEP 


439 


easy victim. Usually since such a person lacks 
energy and does not take much exercise, he is 
also likely to become too fat. 

Sleep, like food, is necessary to existence. 
But too much sleep or too little sleep is harmful. 
As in all other things, temperance in sleep is 
highly advisable. 

When is a person inclined to sleep too much, 
likely to have the greatest inclination to sleep? 

After eating a hearty meal a person inclined to 
sleep too much usually has a tired and sleepy 
feeling. A heavy meal excites the digestive 
activities and thus diverts a considerable quan¬ 
tity of blood from the brain and other parts of 
the body to the digestive organs. In sleep there 
is less blood in the brain than during waking 
hours. Thus a heavy meal, especially if the 
room is warm, brings about the same conditions 
in the brain as during sleep, and induces a desire 
for sleep. After a hearty meal, especially in 
summer, almost any one feels an inclination to 
sleep. In a church or a theater in the evening 
we often find many in the audience nodding. 
If we ask the reason we usually find that these 
persons have just eaten a heavy meal. 

Should we exercise immediately after eating? 
Whenever it is possible, the hour immediately 
following the meal should be devoted to rest, 
even if that rest induces sleep. In fact, those 


440 


HEALTH READER 


who have the leisure to do so would benefit 
by giving way to the desire to sleep after a 
meal. To take a nap after his noonday meal 
is good for the child’s health. The health of 
grown people would also be improved if they 
could sleep for fifteen or thirty minutes after 
the noonday meal. Unfortunately, most people 
have no chance to indulge this desire to sleep. 

Sleep is profoundly influenced by habit. If 
we are in the habit of going to sleep at a certain 
hour we are very apt to become weary and have 
all the symptoms of sleepiness when that hour 
comes. If we postpone our sleep beyond the 
regular hour we do not as a rule become more 
sleepy; for a time the feeling of sleepiness di¬ 
minishes. If a person who is in the habit of 
going to sleep at ten o’clock in the evening is 
kept up until twelve or one o’clock, he then 
usually has great difficulty in falling asleep. 

Usually physical fatigue is supposed to induce 
sleep. But we may be so tired that we cannot 
sleep. Most people are in the habit of sleeping 
at night, when it is dark, and thus are not able 
to sleep in daylight or if there is a brilliant light 
in the bedroom. 

Sitting at the bedside of children and telling 
stories or singing lullabies is wholly out of place. 
The child soon learns that he goes to bed to 
sleep and not to be entertained. 


A STUDY OF SLEEP 


441 


What changes take place in the circulation during 
sleep ? When a person is asleep the heartbeats 
are slower and there is a slight decrease in the 
natural heat of the body. But the temperature 
of the brain is apparently not decreased to any 
extent. Some physiologists believe that there 
is more blood in the brain during sleep than 
during waking hours. Most physiologists, how¬ 
ever, speak of the condition of the brain during 
sleep as anemic , that is, having less blood in it. 

Some experimenters think that there is an 
accumulation of carbon dioxide in the blood, 
and that this is either the cause or the result 
of sleep. It is well known that the amount of 
carbon dioxide excreted from the lungs is less 
during sleep than during the waking hours. 

What effect has sleep on the functions of the 
body? The digestive and absorbing powers of 
the digestive organs are probably increased 
during sleep. The process of breathing becomes 
slower, and often deeper. Sometimes, when the 
nasal passages are obstructed in any way and 
the mouth is open, snoring results. If you keep 
your mouth shut you will not snore. 

How long can a person live without sleep? How 
long a person can live without sleep can be 
determined only by experimental methods that 
are very cruel. For that reason little is known 
about it. The only way animals or human 
^>15 


442 


HEALTH READER 


beings can be kept from sleep is to torture them 
so that the pain produced is stronger than the 
desire for sleep. Then, if this torture is kept 
up until death occurs, who can say whether 
death was caused by lack of sleep or by an 
excess of pain? 

A person in good health may lose one night’s 
sleep without apparent injury, but he cannot 
lose a second night’s sleep without some loss 
of efficiency. Prolonged sleep is much less 
injurious than prolonged wakefulness, though 
prolonged sleep is the sign of some grave dis¬ 
order or change in the activity of the func¬ 
tions of the body, usually of a cerebral (brain) 
character. When an animal cannot be aroused 
by the usual methods, it has passed into what is 
called a state of coma, which usually ends in death. 

Are there other kinds of sleep besides natural 
sleep? Sleep may be induced by various arti¬ 
ficial means. Artificial sleep is most com¬ 
monly induced by means of alcoholic drinks or 
a drug. The drugs which induce sleep are 
called narcotics. Opium and cocaine are types 
of narcotic substances. 

Is there any danger in using such drugs? There 
is great danger in using drugs of this kind. 
They can be given safely only by a physician 
who has personal care of the patient. The 
use of many of these narcotics, especially opium 


A STUDY OF SLEEP 


443 


and its derivatives—morphine, heroin, and 
codeine—and cocaine, tends to produce a habit 
which, when once formed, is very difficult to 
break, and gradually destroys both physical 
and mental health. 

Opium and its derivatives deaden pain, and 
their use is excusable when there is no chance 
for the patient to get well. But so .long as 
there is a chance for the patient to recover it 
is far better never to administer any of these 
temporary reliefs than to cause him to form a 
habit which, after he recovers from sickness, is 
certain to destroy him. 

Cocaine, which is derived from the dried 
leaves of a South American shrub called coca , 
is not a sleep-producing drug. But it has the 
remarkable ability of relieving pain and of 
causing a condition of emotional excitement. 
It is even more of a habit-forming and destruc¬ 
tive drug than morphine, and its victims are 
utterly miserable when deprived of it. There 
is no more dreadful form of slavery than to be 
a morphine or cocaine user. 

Are there any laws to restrict the sale of such 
drugs? Opium and coca leaves and the sub¬ 
stances derived from them cannot be sold in 
this country except under strict regulations. 
Most of the states have strict laws regulat¬ 
ing the sale of these dangerous habit-forming 


444 


HEALTH READER 


drugs, and in many cities there are municipal 
laws to the same effect. Children, especially, 
should be protected from the evils which always 
attend the use of such drugs. 

Is artificial sleep, induced by means of drugs, 
beneficial? As far as rest or restored energy 
is concerned, the sleep induced by the use of 
a narcotic gives very little of the benefit that 
comes from natural rest or real slumber. The 
drug relieves pain, but the possible harmful 
after-effect when the patient recovers is far 
greater than the good it does in relieving pain. 
But the use of narcotics is merciful in the 
treatment of cases that are hopeless and in 
easing the pain of the last hours of life. ' 

What other kinds of sleep are there? Hypno¬ 
tism is a form of sleep in which the sleeper is 
subject to the will of another. No one can 
explain the mystery of hypnotic sleep. The 
person who is under the influence of hypnotism 
knows nothing of his surroundings except as 
determined by the person who has placed him 
under that influence. The hypnotist com¬ 
mands, and the hypnotic obeys involuntarily. 
The hypnotic answers questions sensibly, per¬ 
forms acts of all kinds, and in general does any 
work he is told to do in a satisfactory manner. 
When he is called out of the hypnotic trance by 
the will of the hypnotist he has no memory of 


A STUDY OF SLEEP 


445 


what has taken place. In a way it may be said 
that he has been asleep, though hypnotic slum¬ 
ber is as different from real sleep as the sleep 
induced by the use of opium. The effect of 



A somnambulist 


such sleep has been said to weaken the mental 
power of the person hypnotized. 

What is meant by sleep walking? The person 
who walks in his sleep, often acting exactly as 
if awake, is called a somnambulist , a word de¬ 
rived from two Latin words, somnus , meaning 
“sleep,” and ambulare, meaning “to walk 
about.” The somnambulist gets out of bed, 












446 


HEALTH READER 


goes about the house, sometimes performs won¬ 
derful feats of athletic skill, and does many 
things better than he could have done if awake. 
When awakened the sleep walker has no recol¬ 
lection of anything that has happened. People 
who walk in their sleep often suffer serious 
injury by falling or running into things. 

v Nearly everybody now and then makes some 
movement in his sleep, crying out or talking, 
or sitting up, or gesticulating. These actions 
are usually remembered on waking as having 
taken place in dreams. But the somnambulist 
remembers nothing that occurred in his walk. 
Certain individuals are more subject to sleep 
walking than others. No positive remedy has 
been discovered for this unfortunate trouble. 
As a general thing simple food, outdoor exercise, 
light clothing, and regular habits will diminish 
the tendency to sleep walking and sometimes 
prevent it altogether. 

What is meant by being in a trance? Persons 
who are in a trance are asleep in the sense that 
they have lost consciousness of the external 
world. But their brain often remains active. 
People in a trance write letters, answer ques¬ 
tions, and do many things that they would 
perhaps not be able to do if they were in a 
normal condition. 

There is another form of sleep in which the 


A STUDY OF SLEEP 


447 


body is more or less rigid, sometimes remaining 
in this condition for many hours or even days. 
This form of sleep is called catalepsy. This 
condition is, of course, abnormal, and seems to 
have no relation whatever to natural sleep. In 
other words, it is a disease. 

Is sleep very important? When we consider 
that in a normal life of seventy years we pass 
nearly twenty-three years in sleep, it is evident 
that sleep is very important in its relations to 
our welfare. We are just as much alive while 
asleep as we are while awake, but it is a different 
kind of life. Sleep is a kind of passive life, 
growth, restoration of tissues, rebuilding of the 
broken parts of the system, rest and refreshment. 
From a physical point of view, sleep is quite 
as important as food and much more so than 
clothing. The fact that we spend almost one 
third of our lives asleep should impress us with 
the importance of sleep. Sleep is essential to 
the health of the body. The hours of sleep 
should therefore be ordered as carefully as the 
hours of work or of play. 

QUESTIONS TO HELP THE PUPIL 

i. Have we any knowledge of the world about us while 
we sleep? why not? 2. Could we live without sleep? 
3. What is the purpose of sleep? 4. How much sleep is 
required by young people from six to eighteen years of 
age? 5. Do brain workers need less sleep than muscle 
workers? 6. What is the result if we get too little sleep? 


448 


HEALTH READER 


7. What is insomnia ? 8. Into what may chronic insomnia 

develop? 9. What does sleeplessness tend to hasten? 
io. What is the effect of too much sleep? n. Why does 
a heavy meal cause tiredness and sleepiness? 12. Is it 
beneficial to take a nap immediately after the noonday 
meal? 13. Is sleep much influenced by habit? 14. 
What is coma? 15. May sleep be caused by artificial 
means? 16. Name some narcotics. 17. Why is the use 
of narcotics very dangerous? 18. Is the trade in narcotics 
restricted by law? 19. Is sleep induced by means of 
narcotics beneficial? 20. What is hypnotic sleep? 21. 
What is sleep walking? 22. What may help to prevent 
it? 23. What is a sleep walker called? 24. Name some 
other abnormal forms of sleep. 25. Is sleep essential to 
the health of the body? why? 26. Is it important to 
have regular hours for sleep? 27. About how much of 
our lives do we spend in sleep? 


XXXIV. Physical Exercise 

What is the value of special physical training? 

Ordinarily the child who plays out of doors will 
become thoroughly developed physically. The 
muscles of the legs are developed by walking 
and running, and the muscles of the arms by 
playing ball, drawing carts, and other play 
activities. The deep and rapid breathing which 
vigorous play induces will develop the muscles 
of the chest. Thus most of the child’s muscles 
become developed in play. It is advisable, 
however, to aid and direct such development 
scientifically and to provide special exercise for 
certain needs. For this reason the gymnasium 
is an important aid to the playground. 

What is a gymnasium and how should it be 
equipped? The gymnasium is, as a rule, a closed 
building where exercise may be taken during 
very cold weather, in rainy seasons, and even at 
night. Thus the gymnasium provides a place 
where the important process of physical develop¬ 
ment may be carried on when it would other¬ 
wise be prevented by outdoor conditions. 

When properly equipped, the gymnasium is 
supplied with many different kinds of apparatus 
for physical development. 

The most common appliances included in the 


449 


450 


HEALTH READER 


equipment of a modern gymnasium are poles, 
rings, ladders, swings of various sorts, “horses,” 



Interior of a gymnasium 

trapezes, and merry-go-rounds. Frequently 
also there is a running-track, as well as a swim¬ 
ming pool. In addition provision is made for 
the playing of basket-ball and other forms of 
indoor ball. For exercises on the trapeze, or 
for any other exercises in which there is danger 
of falling, padded floors or cushions should be 
provided. 

The attendant should always take care to have 
















PHYSICAL EXERCISE 


45i 


the gymnasium well ventilated. The tempera¬ 
ture should always be lower than would be agree¬ 
able to any one not engaged in active exercise. 
While the temperature in the living room should 
be kept at sixty-eight to seventy degrees, the 
temperature in the gymnasium may properly 
be kept as low as sixty to sixty-five degrees. 

Are gymnastic exercises of value ? The value of 
gymnastic exercises cannot be denied. Though 
conducted within doors, such exercises, if prop¬ 
erly directed and if the gymnasium is properly 
ventilated, are very beneficial. But the boy 
in the gymnasium needs supervision; in other 
words, his exercises must be performed under 
the direction of a teacher. To turn children 
loose in a gymnasium without any supervision 
or instruction with regard to the use of the 
various appliances found there might do more 
harm than good. 

The instructor or supervisor should endeavor 
especially to prevent excessive physical exertion. 
An unusual strain or fatigue in the muscles of 
the body as a result of too much exercise is 
harmful instead of beneficial. 

What kinds of gymnastic exercises should be 
given? In the gymnasium, children should at 
first go through very simple exercises. The 
exercises should gradually become more difficult 
as the muscular system develops and endurance 


452 


HEALTH READER 


increases. Thus, by gradual training the child 
may learn to perform with ease exercises which 
he otherwise could not have done. Running, 
jumping, swinging, climbing, the swinging of 
Indian clubs, vaulting, and many other exer¬ 
cises are included in the general course of 
instruction. 

A detailed description of the particular forms 
of exercises which should be practiced in the 
gymnasium cannot be given here. The wise and 
scientific superintendent will study each child 
and try to give him exercises in accordance 
with his particular needs. Children become 
very fond of gymnastic work when it is prop¬ 
erly conducted. Its good effects are visible in 
hardened muscles, clearer eyes, greater mental 
activity, and increased physical endurance. 

What is the value of competitive games? 
Competitive games, that is, games played by 
opposing sides, are better than ordinary play 
because of the added zest induced by the desire 
to win a victory. The sport of simply throwing 
or batting a ball is pleasant exercise, but it can 
in no way equal the interest of a game of ball 
in which each side is struggling for the victory. 
For this reason competitive games played in 
the gymnasium or in the open field, under good 
supervision, are effective in promoting physical 
development. 


PHYSICAL EXERCISE 


453 


Are competitive games dangerous? There is 
one danger to be avoided in such games. The 
players are apt to put forth supreme efforts at 
critical moments in the game. Such efforts 
result in excessive strain or fatigue. Some 
games are much more dangerous on this account 
than others. First among such games is foot¬ 



ball, though there is scarcely any game in which 
a child will take part with more enthusiasm. 
For children, the modified Rugby variety of 
football is preferable to the game played by 
college and university students. In football, 
extreme physical exertion is necessary, at least 
for a few moments at a time, in order to win the 
victory. 








454 


HEALTH READER 




.Ast 


Competitive games with less danger to the 
child are baseball, basket-ball, and lawn tennis. 
Tennis, especially, affords excellent physical 
training, and without any very great danger of 
overexertion. Baseball is a national sport, and 
every boy will want to learn to play it. It is 
comparatively safe, full of interest, and requires 
much skill. Every child should be encouraged 
to play baseball or 
some modified form 
of it, such as volley¬ 
ball, indoor baseball, 
and handball. 

Are running games the 
proper thing for children? 
Running competitive 
games are interesting, 
but they require prob¬ 
ably a greater degree 
of physical exertion 
than any other sport. 
There is danger to the heart and the organs 
of circulation in the supreme efforts put forth 
in such games in order to win, and young folks 
especially should not take part in them. 

A few years ago almost everybody rode the 
bicycle for pleasure. Bicycle riding is delightful 
and beneficial, but when long runs at a rapid 
rate of speed are made, as in racing, extreme 



Riding a bicycle. A beneficial 
outdoor exercise 


PHYSICAL EXERCISE 


455 


fatigue and great injury may result. In gen¬ 
eral, competitive games are to be encouraged, 
but always with wise supervision. 

QUESTIONS TO HELP THE PUPIL 

i. Why should children’s play always be scientifically 
directed? 2. What is a gymnasium? 3. Why should 
exercises in a gymnasium be under the supervision of a 
teacher? 4. Is excessive physical exertion in exercise 
or play hurtful? 5. What should be the temperature in 
the gymnasium? 6. What is the result of properly con¬ 
ducted gymnastic work ? 7. Why are competitive games, 

like baseball, beneficial in promoting physical develop¬ 
ment? 8. What danger should be avoided in playing? 

9. How does an unusual strain or fatigue affect the 
muscles ? 10. What are the dangers of competitive games ? 
11. Under what conditions is bipycle riding beneficial? 


XXXV. The Value of Health 


What is the value of health? Children as a 
rule do not realize the money value of health. 
They realize its advantages, its freedom from 
pain, and the opportunity it gives them for en¬ 
joying life. But they do not realize that good 
health is also to be measured in dollars and 
cents. The mental efficiency of the child and 
of the grown person depends more largely on 
good health than on any other factor. Progress 
in school and in college depends to a great extent 
on the health of the individual. Success in the 
office or in the shop depends very largely on 
good health. The value of a citizen to the 
community and to his own family and friends 
is greater or less according to his state of health. 
It is therefore a matter of supreme importance 
for every one to know from his earliest years 
the fundamental facts of nutrition, of exercise, 
and of play, in order to secure a maximum of 
good health in childhood as well as in adult life. 

How is sickness costly? Just as we may regard 
good health as an increase in money value and 
usefulness, so may we measure ill health as a 
loss in money value and usefulness. The sick 
person is not only unable to do useful work or 
456 


THE VALUE OF HEALTH 


457 


earn money, but he is also a burden to his 
family. The cost of professional medical serv¬ 
ice is often very great. Sickness is therefore a 
heavy burden on humanity, and we should do 
everything in our power to avoid it or to get 
rid of it if we are so unfortunate as to have it. 

To be sick is to be useless. From whatever 
point of view we look at the matter, it pays to 
keep well, and it costs a lot of money to be sick. 

The object of study. The object which the 
child has in view, or at least which the parents 
have in view during schooldays, is that he 
or she shall become a useful man or woman. 
Every factor in the training and conduct of the 
child which leads to this result is to be favored 
and promoted. Every obstacle which lies in 
the way of the achievement of this result is to 
be removed if possible. 

Child life, from the physical point of view, 
has too long been neglected. To be healthy, 
well developed, and vigorous is not only the 
privilege but also the duty of every child. The 
harmonious development of all the organs of 
the body in the healthy child promotes the best 
development of the intellect and of the moral 
nature. 

The purpose of writing this Health Reader has 
been to lead the child little by little into a 
knowledge of those things which concern his 


45§ 


HEALTH READER 


physical welfare and a realization that this is 
intimately related to his mental and moral 
welfare. The child who has read and carefully 
studied the principles laid down in this book is 
better prepared to attain health, happiness, and 
success in life than he otherwise would have 
been. 

QUESTIONS TO HELP THE PUPIL 

i. Can good health be measured in dollars and cents 
as well as increased enjoyment of life? 2. Does men¬ 
tal efficiency depend on good health? 3. Does success 
in work depend on good health? 4. Is it a matter 
of supreme importance for every person to know the funda¬ 
mental facts of nutrition, exercise, and play? 5. How 
can ill health be measured? 6. What has been the pur¬ 
pose of the Health Reader studies? 7. What advantage 
has the child who has carefully read and studied these 
health principles? 


A PRONOUNCING VOCABULARY 


abdomen (ab do'men). 
absinthe ( ab'slnth). 
acidity (d sid'i ti). 
adenoids (ad'6 noids). 
albumin (al bu'min). 
alkali (al kd ll). 
alkaline (al'kd lln). 
alkaloids (al'kd loids). 
ambulare (am b66 la'ra). 
amine (am'in; d men'), 
amino (am'i no), 
amylase (am'i las), 
anemia (d ne'mi d). 

Anopheles (d nof'6 lez). 
antiseptic (an'ti sep'tik). 
apparatus (ap'd ra'tws). 
appendicitis (a pen'di si'tis). 
aqueous (a'kwe ms). 
argon (ar'gon). 
aroma (d ro'md). 

Artesian (ar te'zhdn). 
articulate (ar tik'u lat). 
astigmatism (d stig'md tiz’m). 
auditory (6'di to ri). 

bacteriologist (bak te'ri ol'o jist). 
barometer (bd rom'e ter), 
benzoate (ben'zo at), 
beri-beri (ber'i-ber'i). 
beverage (bev'er aj). 
bolus (bo'lMs). 
bronchitis (bror) kl'tis). 

cacao (kd ka'o; kd ka'o). 
caecum (se'kMm). 
caffeine (kaf'6 in; en). 
canine (kd nin'; ka'nin). 
capillaries (kap'i la riz; 

kd pil'd riz). 

Capsicum (kap'si kMm). 
carbohydrate (kar'bo hl'drat). 
carbon dioxide (kar'bon 
dl ok'sld). 

cardiac orifice (kar'di &k br'i fis). 
cartilage (kar'ti laj). 


casein (ka'se in), 
cassava (kd sa'vd). 
catalepsy (k&t'd lep' si), 
catarrh (kd tar'), 
cellulose (sel'u los). 
cereal (se're dl). 
cerebellum (ser'6 bel'din). 
cerebral (ser'6 brdl). 
cerebrum (ser'fe brdm). 
cervical (sur'vi kdl). 
champagne (sham pan'), 
chlorine (klo'rin; ren). 
cholera (kol'er d). 
chyle (kll). 
chyme (klm). 
citric (sit'rik). 
citrous (sit'rds). 
clinical (klin'Ik dl). 
coagulate (kd ag'u lat). 
cocaine (ko'kd in), 
codeine (ko de'in; ko'dd en) 
colon (ko'ldn). 
coma (ko'md). 
competitive (kdm pet'i tiv). 
condiments (kon'di ments). 
congestion (kdn jSs'chdn). 
constituents (kon stit£ ents) 
contagious (kdn ta'jds). 
contralto (kon tral'to). 
cornea (kdr'nd d). 
corpuscle (kdr'pus’l). 
crystalline (kris'tdl in; In). 
Culex (kQ'leks). 
cuticle (ka'ti k’l). 
cutis vera (ku'tis ve'rd). 

dextrin (deks'trin). 
dextrose (deks'tros). 
diabetes (dl'd be'tez). 
diaphragm (dl'd fram). 
diastase (dl'd stas). 
diphtheria (dif the'ri d). 
dorsal (ddr'sdl). 
duodenum (du'o de'ndm). 
dysentery (dis'en ter i). 


459 


4 6o A PRONOUNCING VOCABULARY 


eau de Cologne (o de ko Ion'), 
edible (ed'i b’l). 
emulsion (e mul'shdn). 
entomology (en'to mdro ji). 
environment (en vi'rdn ment). 
enzymes (en'zlmz). 
epidemic (ep'i dem'ik). 
epidermis (ep'i dur'mis). 
epiglottis (ep'i glot'is). 
esophagus (£ sof'd gds). 
eucalyptus (u'kd lip'tds). 
Eustachian (u sta'ki dn). 
excretion (eks kre'shdn). 
excretory (eks'kr& to n). 

fatigue (fa teg'), 
feces (fe'sez). 
fibrin (fl'brin). 
fibrous (fl'brus). 
filaments (fil'd ments). 
formic (fbr'mlk). 
function (fugk'shdn). 

gaseous (gas'e us). 
gastric (gas'trik). 
gelatin (jel'd tin), 
germicide (jur'mi sld). 
gesticulate (jes tik'u lat). 
globules (glob'ulz). 
glucose (gldo'kos). 
gluten (gloo'ten), 
glycerin (glis'er in), 
glycogen (gll'ko jen). 
granary (gran'd ri). 
graphite (graf'lt). 
gullet (gul'et). 
gustatory (giis'td to ri). 

Hawaiian Islands (ha wi'ydn 
I'ldnds). 

heroin (he ro'in; her'o in). 
hordein (hor'de in), 
hydrochloric (hl'dro klo'rik). 
hydrogen (hi'dro ]en). 
hypertrophy (hl'per tr6 fl). 
hypnotism (hip'no tiz’m). 

ileum (il'6 dm), 
incisors (in sl'zerz). 
indol (in'dol; dol). 


infantile (in'fdn til; til), 
infectious (in fek'shds). 
insomnia (in sbm'ni d). 
intestines (in tes'tinz). 
iris (i'ris). 

jejunum (j£ joo'ndm). 
juniper (joo'ni per). 

krypton (krip'ton). 

lacteal (lak'te dl). 
lactose (lak'tos). 
larynx (lar'igks). 
levulose (lev'u los). 
ligament (lig'd ment). 
lipase (lip'as). 
lobule (lob'ul). 
lumbar (lum'bdr). 
lymphatic (lim fat'ik). 

magnesia (mag ne'zhi d). 
maize (maz). 
malaria (md la'ri d). 
malic (ma'lik; mal'ik). 
maltose (mbl'tos; mol'), 
massage (md sazh'). 
masticate (mas'ti kat). 
mastoid (mas'toid). 
medicinal (m6 dis'i ndl). 
medulla oblongata (mfe diil'd 
ob'log ga'td). 
menthol (men'thol; thol). 
mercury (mur'kuri). 
microbes (ml'krobz). 
microscopic (ml'kro skop'ik). 
molar (mo'ldr). 
morphine (mbr'fin; fen), 
mucous (adj.) (mu'kds). 
mucus (noun) ma'kds). 
muscle (mus"l). 

narcotics (nar kbt'iks). 
nasal (na'zdl). 
nectar (nek'tdr). 
neurasthenia (nu'rds the'ni d) 
nicotine (nik'o tin; ten), 
nitrogen (nl'tro jen). 
nitrogenous (nl troj'fe nws). 
nostril (nos'tril). 
nutrients (nu'tri ents). 


A PRONOUNCING VOCABULARY 461 


obesity (6 bes'i ti). 
odor (o'der). 
olfactory (61 f&k'td ri). 
opaque (6 pak'). 
opium (o'pi Mm), 
optic (6p'tik). 
oxidizing (ok'si dlz'ing). 
oxygen (ok'si jen). 

palate (pal'at). 
pancreas (pag'kr£ as), 
papillae (pd pil'e). 
paralysis (pa ral'i sis). 
parasites (par'd sits), 
parotid (pd rot'id). 
pecan (p£ kan'; kan'). 
pellagra (pe lag'rd; lag'rd). 
pepsin (pep'sin), 
percolate (ptir'ko lat). 
peroxide (per ok'sld). 
perspiration (pdr'spi ra'shwn). 
petroleum (p6 tro'16 um). 
phagocytes (fag'o sits), 
pharynx (far'igks). 
phenol (fe'nol; nol). 
phosphate (fos'fat). 
phosphoric acid (f6s for'ik as'id) 
phosphorus (fos'for ms; fo rus). 
plasma (plaz'md). 
pleura (ploo'rd). 
pneumonia (nu mo'ni d). 
pollen (p61'en). 
pons (ponz). 
porous (po'rMs). 
posterior (p6s te'ri er). 
potash (pot'ash). 
protein (pro't£ in), 
ptyalin (tl'd lin). 
pungency (pim'jen si), 
pupa (pu'pd). 
pylorus (pi lo' tms; pi). 

quinine (kwl'nln; kwi nen'). 

rancid (ran'sid). 
rectum (rek'tMm). 
recuperate (re ku'per at), 
refrigeration (r6 frij'er a'shMn). 
register (rej'is ter), 
rennet (ren'et; it). 


rennin (ren'ln). 
respiratory (r£ spir'd to ri; 

res'pi rd). 
retina (ret'i nd). 
rigid (rij'id). 

Rio de Janeiro (re'o da zhd na'ro). 
ruminant (roo'mi nant). 

sago (sa'go). 
saliva (sd ll'vd). 
salivary (sal'i va ri). 
sarcophagus (sar kof'd gMs). 
sarsaparilla (sar'sd pd ril'd), 
sclerotic (skle rot'ik). 
secretion (s6 kre'shmi). 
sensory (sen'so ri). 
serum (se'rMm). 
skatol (skat'ol; 61). 
soluble (sol'ta b’l). 
solvent (sol'vent). 
somnambulist (som nam'bu list) 
somnus (som'nus). 
soprano (so pra'no). 
sorghum (sbr'gMm). 
sputum (spu'tMm). 
steapsin (st6 ap'sin). 

Stegomyia (steg'o mi'yd). 
sterile (ster'il). 
sternum (sttir'nMm). 
stimulus (stim'u 1 ms). 
sublingual (sub lig'gwal). 
submaxillary (sub mak'si la ri). 
succulent (suk'u lent), 
sulphur (sul'fMr). 

tannin (t&n'in). 

taro (ta'ro). 

tartaric (tar tar'ik). 

technical (tek'ni kdl). 

technique (tek'nek). 

theine (the'in; en). 

theobromine (the'6 bro'mtn). 

thermometer (ther m6m'6 ter). 

thoracic (tho r&s'ik). 

thorax (tho raks). 

tissue (tish'ti). 

tongue (tung). 

tonsils (ton'sils). 

trachea (tra'ke d; trd ke'd). 

trypsin (trip'sin). 


462 


A PRONOUNCING VOCABULARY 


tubercle bacillus (tG'ber k’l 
b d sil'ws). 

tuberculosis (tli ber'ku lo'sis). 
tympanum (tim'pd num). 
typhoid fever (tl'foid fe'ver). 

urea (a'r£ a). 
ureter (u re'ter). 
urethra (u re'thra). 
uric (G'rik). 
urine (G'rin). 
uvula (G'vu Id). 

vacuum (vak'G um). 
velocity (v6 los'i ti). 


venous (ve'nws). 
vertebrae (vfir'te bre). 
villi (vil'i). 
viscid (visId), 
vitamine (vl'td min), 
vitreous (vit'r£ ms). 
vitrified (vit'ri fid). 

whooping cough (hobp'ing k 5 f). 

xenon (zen'on; ze'non). 

zein (ze'in). 


THE INDEX 


Absinthe, 260. 

Absorption of foods, 361-365. 

Acid in the stomach, character 
of the, 333-336; excess of, 340. 

Acids, in foods, 152-153; in 
fruits, 152, 197. 

Adenoids, 46-47. 

Air, 1-20; composition of, 9-14; 
contamination of, 74-75; 
depth of, 8-9; dust in, 16, 
64-72; elements of the, 6-20; 
impure, 14-16; natural con¬ 
stituents of, 13-14; necessary 
to life, 16-18; pure, 13-14; re¬ 
lation of fire and, 89-90; result 
of lack of fresh, 19-20; stag¬ 
nant, 74; weight of, 3-5. 

Air passages of head and throat, 

4°. 

Albumin in the urine, 359. 

Alcoholic beverages, 115, 256- 
261; lower efficiency, 260-261. 

Ale, 258. 

Alimentary canal, 351-353; mu¬ 
cous membrane of, 364. 

Alkali, 164. 

Alkaloids, 244,255; in soft drinks, 
254-256; in, tobacco, 262. 

Amino acids, 349, 359. 

Amylase, see Diastase. 

Anemia, 176, 371. 

Animal foods, 201-211. 

Anopheles, 58-59. 

Antiseptics, 35. 

Appendicitis, 199. 

Aqueous humor, 396. 

Argon, 12-13. 

Arteries, 366, 368, 369; of the 
heart, 26, 27, 28. 

Artesian wells, 119. 

Ascending colon, 353. 

Astigmatism, 399. 

Atlas, 379. 

Auditory nerve, 416. 

Axis, 380. 


Back, see Dorsal. 

Backbone, 23, 30, 379. 

Bacteria, in blood, 372; in large 
intestine, 354~356. 

Barley, 145, 158; as food, 172- 
174; beer made from, 172, 
2 57~ 2 58; composition of, 173. 

Bath, daily, 109; temperature 
of, 109-110. 

Bed clothing, 102. 

Beer, 172, 257-258. 

Beri-beri, 176. 

Beverages, 116-117, 234-261; 
distilled, 259-260. 

Bile, 344-347; formation of, 347; 
function in digestion, 347. 

Bladder, 357-358, 360. 

Blindness, 396-398. 

Blood, 366-374; circulation of, 
84-88; circulation of, through 
the lungs, 25-28; clotting of, 
366-367; condition of, during 
sleep, 441-442; constituents 
of, 366-368; definition of, 
366; functions of, 368; in 
arteries and veins, 27; pres¬ 
sure of, 369-371; purifiers of, 
37 2 ~373; red corpuscles of, 
87, 367; result of less than 
normal amount, 371-372; re¬ 
sult of more than normal 
amount, 369-370; sugar in, 
363; use of, 84-88; white 
corpuscles of, 31, 32, 87, 88, 
367, 368. 

Body, food elements necessary 
for growth of, 283-313; tem¬ 
perature of, 93-103; water in, 
114. 

Bolus, 329-330. 

Brain, divisions of, 378; func- 

' tions of, 375-378; relation of 
nerves to the, 376; relation of 
spinal cord to the, 376; weight 
of the, 378-379- 


463 


464 


THE INDEX 


Bran, 162, 163, 181; vitamines 
in, 180. 

Brandy, 259-260. 

Bread, 142-143, 186-192; as a 
universal food, 143; corn, 188; 
rye, 188; wheat, 187. 

Breastbone, 30, 31. 

Breathing, 18-20; experiment 
illustrating, 24-25; fish’s man¬ 
ner of, 37-38; organs of, 21-57. 

Bright’s disease, 359. 

Bronchial tubes, 21, 22, 30, 40. 

Buckwheat, 145, 158; flour 

made from, 189. 

Butter, 150, 187, 219. 

Caecum, 252. 

Caffeine, 244, 245, 252, 254; in 
cocoa and chocolate, 116, 117, 
252, 253; in relation to health, 
245; in soft drinks, 254, 255. 

Cake, 190-192. 

Candy, 265-271; effect of, on 
health, 269-270; effect of, on 
teeth, 270-271; ingredients of, 
266-267, 268, 269; injurious 
substances in, 268, 269. 

Canning of foods, 216, 217, 
222-224. 

Capillaries, 84, 369. 

Carbohydrates, 144, 145, 285, 
294-298; in properly balanced 
diet, 305; in small intestines, 
344; used in building the 
body, 297, 298. 

Carbolic acid, 354. 

Carbon, 90, 91, 92, ill, 112. 

Carbon dioxide, 10-12, 20, 23, 
27, 86, 91, 92, hi; in blood, 
3 6 9-370; in breath, 28, 29. 

Carbonic acid, 235, 236. 

Cardiac orifice, 333. 

Casein, 156. 

Catalepsy, 447. 

Cataract, of the eyes, 397. 

Catarrh, precautions to prevent, 
47 - 52 . 

Catchup, 222-224. 

Cell eaters, 87. 

Cellulose, 265. 


Cereals, 145-148, 158, 285; as 
food, 158-181; beer made 
from, 257; containing starch, 
296; whisky made from, 259. 

Cervical (neck), 380. 

Champagne, 258. 

Chest, 21, 30, 31. 

Chewing, 329. 

Child, coffee harmful to, 245- 
246; diet for the, 322; effect 
of soft drinks on health of, 
255; food for the growing, 
158; fruits for, 198-199; pro¬ 
tein necessary for diet of, 293- 
294; tea harmful to, 247-248; 
temperature of bath for, no. 

Chlorine, 151. 

Chocolate, 253-254. 

Choking, 43-44. 

Chyle, 349. 

Chyme, 341. 

Cigarettes, harmful, 263-264. 

Circulation of the blood, 84-88; 
during sleep, 441; through the 
lungs, 25-28. 

Citric acid, 153, 197. 

Cleanliness, in relation to health, 
108-109. 

Clothing, for children, 97, 101, 
102; wearing of, 96, 97, 98. 

Clots, blood, 366, 367. 

Coca-cola, 117. 

Cocaine,442; and soft drinks,255. 

Cocoa, 252, 253. 

Coffee, 242-246. 

Colds, 52-56; precautions to 
prevent, 47-52; remedies for, 
56; sense of smell affected by, 
407 - 

Cold storage, 203, 207, 208, 217- 
220. 

Colon, ascending, 352-354; de¬ 
scending, 352-354; transverse, 
352 - 354 . 

Coma, 442. 

Combustion, a study of, 89-92. 

Condiments, 132-135, 285, 365; 
as food, 141; danger in exces¬ 
sive use of, 140; necessary for 
building of body, 303-304. 


THE INDEX 


465 


Confections, 265; sugars, pas¬ 
tries, 265-282. 

Corn, 145, 158; as a food, 165- 
168; composition of, 166; dif¬ 
ference between barley and, 
173; difference between rye 
and, 171; in relation to health, 
169, 170. 

Cornea, 394, 395. 

Corn meal, 168, 189. 

Corpuscles of the blood: red, see 
Blood, red corpuscles; white, 
see Blood, white corpuscles. 

Cotton-seed oil, 150, 187. 

Cross-eyes, 400. 

Crystalline lens, 395, 397, 398. 

Culex, 58-59. 

Cuticle, 104. 

Cutis vera, or true skin, 105. 

Dental inspection in public 
schools, 325-327. 

Descending colon, 352-354. 

Dextrin, 324. 

Dextrose, 349. 

Diabetes, 149, 359. 

Diaphragm, 23, 36, 333. 

Diastase (amylase), 348. 

Diet, relation of hunger to 
proper control of, 432; relative 
proportion of foods in proper, 
305-308; simplicity a factor in, 
310-312. 

Digestion, 315-356; condiments 

aid, 136-137, 138, 140, 304; 

carbohydrates in relation to, 
294-295; in small intestine, 
342-344; in stomach, 335- 
336; sociability an aid to, 312- 
313; teeth important in, 316; 
the spleen in relation to, 350, 
351 - 

Digestive ferments, 336-340; 
action of the, 338-339; se¬ 
creted by pancreas, 348, 349. 

Digestive fluids, 339, 340. 

Digestive organs, 3 I 5 ~ 354 ; af¬ 
fected by tobacco, 262, 263; 
relation of smell and taste to, 
139 - 


Diseases of kidneys, 358-360. 

Diseases of lungs, 31-35. 

Distilled liquors, 259, 260. 

Distilled waters, 118. 

Dorsal (back), 380. 

Drinking water, pure, 118, 119; 
purifying, 120, 121; tempera¬ 
ture of, 117. 

Drinking while chewing, 121- 
122, 239, 331 - 332 . 

Drinks, 7, 234-261; alcoholic, 
115, 256-261; soft, 116, 254- 
256. 

Drugs producing sleep, 442-444. 

Dumb bells, exercises with, 52. 

Duodenum, 343. 

Dust, definition of, 64; in the 
air, 64-72; in the lungs, 65; 
in the water, 65; tuberculosis 
germs in, 69, 70. 

Ear, 46, 416-421; diseases of, 
420; external, 416; in relation 
to health, 420; internal, 416- 
418; middle, 416-418; trans¬ 
mitting apparatus of, 417, 
418, 419. 

Ear drum, 416-417, 419. 

Eating, rest after, 439-440; re¬ 
sult of drinking water when, 
121-123, 239; rule to observe 
when, 310-312; sociability in 
relation to, 312-313; use of 
liquids when, 331-332. 

Eggs, 150, 201, 218, 288. 

Enzymes, 324, 338 - 339 , 348- 

Epidermis, 104. 

Epiglottis, 41, 42, 43, 44. 

Esophagus, 40, 41-44, 45; in re¬ 
lation to stomach, 333; in 
relation to swallowing, 329- 
331; in relation to vomiting, 
330 . 

Eustachian tube, 46, 417, 420. 

Exercise, 47-50; for children, 47- 
48; gymnastic, 48-49; kinds 
of, 451-455; not immediately 
after eating, 439-440; out-of- 
doors preferable, 50; physical, 
449-455; value of, 449. 


466 


THE INDEX 


Eyes, 392-404; as affected by 
measles, 403, 404; cause of 
color, 396; defects of, 396-400; 
fluids of, 396; in relation to 
health, 402; light in relation 
to, 393,402; parts of, 394-396 

Farsightedness, 398. 

Fat, 150, 285; absorption of, 349, 
363; excess of in tissues, 299- 
300; in meat, 209; in properly 
balanced diet, 305; study of, 
298-300; use of in body 
building, 298-299. 

Fatty acids, 349. 

Feces, 353. 

Feeling, sense of, see Touch, 
sense of. 

Fermentation, 254, 256-260; 

cause of, 256-257. 

Fermented beverages, 256-261; 
relation to health, 258. 

Ferments, digestive, 336-339. 

Fever, 95, 99, 100; water used in 
case of, 125-126. 

Fibrin, 366. 

Filtration of water, 120. 

Finger nails, 105. 

Fire, relation of air and, 89. 

Fish, 201, 204, 207, 285; manner 
of breathing, 37-38. 

Flavor of food, 136-141; Sense 
of smell in relation to, 136,408. 

Flesh as food, 201, 204-207. 

Flies, 61-63. 

Flour, 162-164; grades of, 162. 

Food, 129-225; absorption of, 
361-365; acids in, 151-153; 
animal, 285; articles of, 131- 
135; a study of, 283-313; 
carbohydrates, 144, 145, 285, 
294-298; cereals as, 158, 179; 
chewing of, 315-316; classi¬ 
fication of, 144, 145, 285; 
composition of, 155-179; con¬ 
diments, 132-135, 285; con¬ 
taining carbohydrates, 295- 
297; containing iron, 286; con¬ 
taining minerals, 285,286-2871 
containing protein, 287-294; 


containing starch, 295-296; 
containing sugar, 295, 296; 
cooked and raw, 285; correct 
proportion of mineral, 286- 
287; definition of, 130; ele¬ 
ments of, 142-152; exit from 
stomach of, 341-342; fats and 
oils as, 298-300; flavor of, 
136-141; for growing child, 
155— r 58; function of starches 
in, 294-295; function of sugars 
in, 294-295; furnished by ani¬ 
mals, 201-211; honey as a, 
276; in different countries, 
145; ingredients of, 305-307; 
in relation to development of 
body, 283-313; in relation to 
heat of body, 98-99; in stom¬ 
ach, 98; methods of preserv¬ 
ing, 214-224; mineral, 285- 
287; mineral substances in, 
151; necessary to effective 
work, 129-130; necessary to 
health and growth, 129-130; 
necessary to life, 127; nitro¬ 
genous, 285, 287-294; nuts as, 
226-233; of animals, - classes, 
285; oils and fats, 285; prepar¬ 
ation of, 285; preserving, 212- 
225; products, not absorbed in 
the stomach, 362; purpose of, 
283-285; rich in starch and 
sugar, 295-297; starches and 
sugars as, 144-149; study of 
articles of, 153-185; universal, 
bread, meat and vegetables, 
143-145; varieties of, 142-154; 
vegetable, 285; where ab¬ 
sorbed, 352-365; wholesome¬ 
ness of as affected by temper¬ 
ature, 414-416. 

Food and Drugs Act, 141. 

Formic acid, 275-276. 

Fowl, 201, 204, 207, 208. 

Fruits, 137, 148, 193-200, 285; 
acids in, 152, 196-197; as 
food, 143-144; distinguishing 
characteristics of, 195; effect 
on human, system of seeds of, 
198-200; in relation to health, 


THE INDEX 


467 


196; methods of preserving, 
212, 213, 214, 220, 224; raw 
and cooked, 197-198. 

Gall, 344; bladder, 344-345- 

Game, 285. 

Games, running, 454, 455; value 
in education, 49; value of 
competitive, 452, 453, 454. 

Gas, 7. 

Gin, 259-260. 

Ginger ale, 255. 

Glucose, definition of, 272-273; 
used in candy, 269. 

Gluten, 167, 364. 

Glycerin, in small intestine, 349. 

Glycogen, 346,363- 

Grape juice, 258-259. 

Griddle cakes, 188-189. 

Gullet, 40. 

Gum chewing, 329. 

Gustatory nerve, 410. 

Gymnasium, equipment of, 449. 

Gymnastic exercises, 449-452; 
value of, 451. 

Hair, 105, 106. 

Health, alcohol in relation to, 
258; candy and, 263; cleanli¬ 
ness in relation to, 108-109; 
ear in relation to, 420; eye in 
relation to, 402; honey and, 
277; how flies endanger, 61, 
62; how mosquitoes endanger, 
58, 59, 60; light and, 402; nuts 
and, 231; sense of smell and, 
408; sense of taste and, 414; 
sense of touch and, 427; sirup 
and, 274-275; sour milk and, 
241-242; value of, 256, 458; 
water and its function in, 
108-110. 

Hearing, sense of, 416-421. 

Heart, 25, 26, 35; action of the, 
84; affected by tobacco, 262- 
263; relation of action of 
lungs to action of, 50, 51. 

Heartburn, 340-341. 

Height for grown person related 
to weight, 300. 


Hoarseness, 43. 

Hominy, 170. 

Honey, 275-277; food value of, 
276-277; formic acid in, 275- 
276; in relation to health, 277. 

Hops, beer made from, 257-258. 

Hordein, 364. 

Hunger, relation to proper diet, 
432; sense of, 431-432. 

Hydrochloric acid, 337-338; 
amount in stomach, 340. 

Hydrogen, 92, 111-112, 149, 
150. 

Hypnotism, 444. 

Ice cream, 280-281; food value 
of, 281-282; for children, 282. 

Ileo-caecal valve, 352. 

Ileum, 343. 

Incisors, 316, 317. 

Indol, 354. 

Infantile paralysis, 381. 

Insomnia, 437, 438. 

Intestine (large), bacteria in, 
354; function of, 352-353; 
study of, 351-354. 

Intestine (small), 342, 343, 344; 
food in the, 344; function of, 
343-344; length of, 343. 

Involuntary movements, 387- 
388. 

Iodine, 286. 

Iris, 395. 396. 

Iron, 119, 151; foods containing 
most, 286; in spleen, 349; sul¬ 
phate of, 121. 

Jaws, 316. 

Jejunum, 343. 

Jelly, 224. 

Keller, Helen, and sense of 
touch, 423. 

Kidneys, 354; diseases of, 358- 
360; function of, 357; impor¬ 
tant for health, 358; location 
of the, 357; size of, 358; study 
of, 357-360. 

Krypton, 13. 


468 


THE INDEX 


Lacteals, 363. 

Lactose, 156. 

Larynx, 22, 41-43. 

Lenses of the eye, 395-397. 

Levulose, 349. 

Ligaments, 380. 

Light, in relation to eyes, 402; 
in relation to health, 402, 403. 

Lime, 29, 119, 121, 151, 197, 
285, 286. 

Lipase (steapsin), 349. 

Liquors, 256-261; distilled, 259- 
261; fermented, 256-259. 

Liver, 36, 344; functions of the, 
345-347, 363; location of, 345; 
secretions from, 344, 346; size 
of, 345; veins and arteries in, 
345, 346; weight of, 345. 

Loins, see Lumbar. 

Lumbar (loins), 380. 

Lungs, 21-57, 94, 96; affected 
by tobacco, 262-263; blood 
vessels of, 25-28; cells in the, 
21, 25; circulation of blood in, 
25-28; difference between 
right and left, 35-37; diseases 
3 I- 35i how air enters, 39- 
40; lobule of, 36; Nature’s 
protection of, 30, 31, 67; 
relation of heart action to, 50. 

Lymphatics, 363. 

Magnesia, 119, 151, 286. 

Maize, see Corn. 

Malaria, 58. 

Malic acid, 153, 197. 

Malt, 172. 

Maltose (malt sugar), 349. 

Massage, 125. 

Mastoid bone, 420. 

Matter, forms of, 6-8. 

Meals, liquids with, 332; re¬ 
quired in a day, 342; rest 
after, 439-440; rule to observe 
when eating, 310-311; water 
with, 121-123, 239. 

Meat, 142-148, 201-211, 285; 
age at which to begin eating, 
202-203 5 and cold storage, 
203, 207, 208; a universal 


food, 143-145; composition of, 
208-211; cured, 203; diges¬ 
tion of, 204; methods of pre¬ 
serving, 203, 204, 207-208; 
most suitable for food, 204- 
208; red, 205; white, 205. 

Milk, 155, 201, 285, 293; com¬ 
position of, 155-158; for grow¬ 
ing children, 293-294; sour, 
effects of, 241; sugar in, 147- 
148; time to drink, 240-241; 
tuberculosis germs in, 34. 

Mineral foods, 285; study of, 
285-287. 

Mineral substances, 151; com¬ 
monly omitted from ration, 
303; how absorbed, 365; in 
drinking water, 126, 234; 

necessary to body building, 

303. 

Molars, 316. 

Mosquitoes, 58-61. 

Motor nerves, see Nerves, motor. 

Mouth, 39-45; glands opening 
into, 40; pneumonia germ in, 
35 - 

Movements, voluntary and in¬ 
voluntary, 388-389. 

Mucous membrane, 336, 361; of 
nostrils, 39. 

Mucus, 39, 361; necessary to 
alimentary canal, 361. 

Narcotics, sleep induced by, 
442-443. 

Narrow ratio, 306. 

Nasal passages, 45. 

Nearsightedness, 398. 

Neck, see Cervical. 

Nerves, 385-391; definition, 385; 
function of the, 385; injured 
by tobacco, 262-263; location 
of, 385; motor, 389, 390; of 
hearing, 416; of sense of smell, 
404-405; of sight, 392-394; 
of sense of taste, 409-416; 
of sense of touch, 422-429; 
of the skin, 105-106; sensory, 
I0 5> 389, 390; speed of trans¬ 
mission through, 386, 387. 


THE INDEX 


469 


Nervous system, a study of, 
375-391- 

Neurasthenia, 438. 

Nicotine, 262. 

Nitrogen, 10, 149; foods con¬ 
taining, 285, 287-294. 

Nostrils, 39. 

Nutrition, elements of, 153-185; 
principles of, 301-313. 

Nutritive ratio, 305; standard, 
306, 307. 

Nuts, 150, 285; as food, 226-233: 
danger in eating, 231; in rela¬ 
tion to health, 231-233; raw 
and roasted, 226; varieties of, 
227-230. 

Oatmeal, 177. 

Oats, 145; as food, 177-179; 
composition of, 177. 

Odors, 14-16. 

Oil, 150, 285. 

Oils, edible, 150; function in 
nutrition, 299; study of, 298- 
300; use of in body building, 
298-299. 

Olfactory nerve, 139, 404, 405; 
affected by colds, 407. 

Olive oil, 150, 187. 

Opium, 442. 

Optic nerve, 392-394, 396, 397; 
defective, 397. 

Oxygen, 10, 11, 12, 14, 20, 22, 23, 
26, 27, 28, 89, 90, 91, 92, hi, 
149, 150; as a food, 131-132; 
in the blood, 369, 370. 

Pain, ability to localize the sen¬ 
sations of, 427-428; in rela¬ 
tion to sense of touch, 425- 
426. 

Palate, 44, 45. 

Pancreas, 140, 345, 347-349; lo¬ 
cation of, 347; secretions of, 
347-348, 349. 

Papillae, of the tongue, 409-410. 

Paralysis, 381. 

Parotid glands, 328. 

Pastry, 278-280; and digestion, 
279-280. 


Pellagra, 169. 

Pepsin, 139, 337. 

Peptone, 337-338; in small 
intestine, 344. 

Perspiration, 95. 

Phagocytes, 87. 

Pharynx, 45-46; in relation to 
thirst, 433. 

Phenol, 354. 

Phonograph, compared to ear 
drum, 419-420. 

Phosphate, 285. 

Phosphoric acid, 149, 286. 

Phosphorus, 151. 

Physical exercise, 449-455. 

Pickling, of foods, 221-223. 

Pie, see Pastry. 

Plants, and carbon dioxide, 10- 
12, 23; producing sugar, 265- 
266. 

Plasma, 366. 

Pleura, 23, 30, 31. 

Pneumonia germ, 32, 35, 36, 37. 

Portal vein, 362. 

Potash, 151, 164, 197, 285, 286. 

Poultry, 211, 219-220, 285. 

Preserving foods, 212-225. 

Protein, 149-150, 163, 166, 171, 
173, 175, 1 77, 178, 208, 285, 
287-294; absorption of, 344; 
amount necessary, 289-290; 
as digested in the stomach, 
337-338; certain kinds more 
easily absorbed, 364-365; foods 
containing, 287-294; in bran, 
264; in properly balanced diet, 
305; in vegetable foods, 288- 
289; lean meat a source of, 
285; milk a source of, 285- 
286; nutritive qualities of, 
290-294; sources of, 287-289. 

Ptyalin, 348. 

Pupil of the eye, 395. 

Pure food law, 141. 

Pylorus, 333. 

Ration, study of balanced, 301- 
3i3- 

Rectum, 353. 

Rennin, 336 - 337 * 


470 


THE INDEX 


Retina, 392, 395. 

Ribs, 21, 30, 31. 

Rice, 145-146; as a food, 174- 
176; composition of, 175; pre¬ 
paration of for eating, 175-176. 

Root beers, 254. 

Rum, 259-260. 

Rye, 145, 158, 170-171; as a 
food, 170-171; bread made of, 
171; composition of, 171. 


Sago, 146. 

Saliva, 40, 122, 239, 323; and 
digestion, 327-329. 

Salivary glands, 40, 122, 139, 
239, 3 2 7; and their function, 
327-329. 

Salt, 132-135; necessary to hu¬ 
man body, 303-304. 

Sclerotic coat of eye, 394. 

Senses, the, 392-433; substitu¬ 
tion of the, 430-431. 

Sensory nerves, 105, 388-390. 

Serum, 366. 

Sickness, 99-100. 

Sirup, 147, 189, 190, 192, 271- 
277; food value of, 273; glucose 
in, 272-273; how made, 272; in 
relation to health, 274-275; 
maple, 172, 189; mineral sub¬ 
stances in, 273-274; sorghum, 
265, 272; used in candy, 267- 
268; value other than food, 
273-274. 

Skatol, 354. 

Skin, 104; and functions of, 104, 
106-109; chief organ of sense 
of touch, 423; cleansing of, 
108-109; structure of, 104- 
106; temperature of the body 
controlled by, 106-109. 

Skull, 375-378; relation to spinal 
column, 379. 

Sleep, 436, 447; artificial, 442- 
444; changes in circulation 
during, 441; digestive power 
during, 441; drugs producing, 
442; effect of too much, 438- 
439; effect on bodily func¬ 
tions, 441; how long should 


we, 436-437; importance of, 
447; result of too little, 437; 
various kinds of, 444-445; 
walking in, 445. 

Sleepiness, overeating a cause 
of, 439 - 

Sleeping, covering when, 102; 
temperature of rooms for, 82. 

Smell, nerve of, 139, 404-408; 
effect of colds on the sense of, 
407; relation of sense of to 
flavor, 408; relation of sense 
of to health, 408. 

Sneezing, 53-54. 

Snoring, 441. 

Soda, 151, 164, 197, 285, 286, 
338; benzoate of, 133. 

Soft drinks, see Drinks, soft; 
effect on health of child, 255; 
varieties of, 254-259. 

Solid, 7. 

Solvent, water a, 112, 113. 

Somnambulist, 445-446. 

Sore eyes, 401. 

Sound, sensation of, 417-421. 

Spinal column, 23, 379; spinal 
cord in relation to, 379-380. 

Spinal cord, 379-384; definition, 
379; function of, 383, 384; 
location of, 379-380; structure 
of, 383 - 384 - 

Spine, 379; curvature of, 381- 
382. 

Spleen, changes in size of, 350; 
function of, 349-351; location 
of, 349 - 350 ; size of, 351; 
study of, 349-351- 

Spring fever, 373 - 374 - 

Standard nutritive ratio, 306- 

307. 

Starch, 144-145, 172. 

Starch foods, 144-146, 295-297. 

Starches, function in food, see 
Foods, function of starches in. 

Starvation, 432. 

Steapsin, see Lipase. 

Stegomyia, 59. 

Sternum, see Breastbone. 

Stomach, absorption of food in, 
337 - 338 ; acid in, 339 - 34 D 


THE INDEX 


471 


definition of, 333; exit of food 
from, 341-342; function of in 
digestion, 333~34 2 ; glands of, 
336; in relation to hunger, 
431-432; length of time food 
remains in, 342; location of, 
333; movements of, 334“338; 
relation to esophagus, 333; 
size of, 333, 334; special, of 
cow and sheep, 331; walls of, 
334> 335J weight of, 334. 

Sublingual glands, 328. 

Submaxillary glands, 328. 

Sugar, 144 - 145 , H 7 -I 49 , 152, 
156, 157 , 159, 166, 171, 172, 
173, 176, 177, 178, 285; func¬ 
tion in foods, 294-295; in fruits, 
148, 196; in liver, 347; in 
milk, 147; in relation to 
health, 148-149; in the urine, 
358-359; in vegetables, 148; 
solubility of, 145; sources of, 
265-266; used in candy, 265- 
267. 

Sugar beets, 152, 266. 

Sugar cane, 152, 265-266. 

Sugar foods, 147-148, 294-298. 

Sulphur, 149, 151. 

Swallowing, a study of, 329-332. 

Sweat, 95-96; glands, 105-107. 

Symond’s table of height and 
weight, 300. 

Tannin, 244, 248. 

Taro, 146. 

Tartaric acid, 153, 197. 

Taste, condition of material to 
produce, 412, 413; effect of 
temperature on, 413-414; in 
relation to health, 414; kinds 
of, 410-411; nerves of, 139, 
409, 410; theory of transmis¬ 
sion of sense of, 41.1-412; 
the sense of, 409-416; tongue 
in relation to, 409, 410. 

Taste buds, 410. 

Tea, 244, 246-252. 

Teeth, 39; and their uses, 315- 
327; canine, 317; care of 
temporary, 321-322; compo¬ 


sition of, 318-319; cutting the, 
319-321; developing good, 

322- 323; effect of candy on, 
270-271; functions of various, 
316; important in digestion, 
316; public school inspection 
of, 325-327; relation to health, 

323- 325; temporary, 316-317, 
321-322; wisdom, 317-318. 

Teething, 320. 

Temperature, 78-83; evils of 
high, 79-80; favorable to 
efficient work, 78; for bed¬ 
room, 82-83; f° r schoolroom, 
48; obstacles to perfect, 81,82; 
of the bath, 109-110; used 
in cold storage, 218. 

Temperature of the body, 93- 
103; clothing in relation to, 
96^98; how kept normal, 94- 
96; how measured, 101; in¬ 
crease in, 99, 100; in state of 
health, 93-100; lungs in rela¬ 
tion to, 95, 96; methods of 
controlling, 98, 99; skin in 
relation to, 95-96. 

Theine, 244, 248. 

Theobromine, in cocoa and 
chocolate, 252-253. 

Thirst, 114-117, 124; sense of, 
333 - 

Thoracic duct, 363. 

Thorax, 21, 30, 31. 

Throat, air passages of, 40. 

Tissues, of the body, 144; re¬ 
ceive food from blood, 84, 85. 

Tobacco, 262-264. 

Toe nails, 105. 

Tongue, 39; in relation to the 
sense of taste, 409, 410. 

Tonsils, 40, 45. 

Touch, sense of, 104, 422-431; 
cultivation of the sense of, 
428-429; relation of sense of 
to health, 427. 

Trachea, 21, 30, 40-44. 

Trance, 446. 

Transverse colon, 353. 

Trunk, 23. 


472 


THE INDEX 


Trypsin, relation to digestion of 
protein, 348; relation to pep¬ 
sin, 348. 

Tubercle bacillus, 33. 

Tuberculosis, 32-34; prevention 
of, 33-35; spread of, 70. 

Tuberculosis germs, in dust, 69- 
70; in milk, 34; protection 
against, 70-72. 

Tympanum, 416-417, 419. 

“Universal solvent,” 113. 

Urea, 292, 347, 357, 358. 

Ureter, 358. 

Urethra, 358. 

Urine, 354, 357, 359; principal 
constituent of, 357; separated 
from blood by kidney?, 357. 

Uvula, 44. 

Vacuum, 8. 

Vacuum cleaner, 69. 

Vegetables, 143-145, I 48, I93~ 
200; containing iron, 286; 
containing protein, 288-289; 
containing starch, 157, 295- 
296; methods of preserving, 
214-224; protein in, 288. 

Vegetable oils, 187. 

Veins, 366, 369; blood in the, 
25, 26; of the heart, 25, 26. 

Ventilation, 73-77; definition 
of, 73; best methods of, 75- 
77; hindrances to, 74-75; 
why necessary, 73-75. 

Vertebrae, 379-380. 

Villi, 362; capillaries in, 362. 

Vitamines, 179-185; aid diges¬ 
tion, 182; as food element, 
151-152, 179; chemical con¬ 
stitution of, 181-182; effect 
of chemicals on, 183; effect of 
heat on, 182-183; health les¬ 
sons learned from discovery 
of, 184-185; important to 
health, 184-185; in bran, 180; 
kinds of, 184. 

Vitreous humor, 394, 396. 

Vocal cords, 42-43. 

Voice, bass, 43; contralto, 43; 
soprano, 43; tenor, 43. 


Voluntary movements, 387-388. 

Vomiting, 330. 

Water, a constituent of blood, 
366; a food, 131; amount re¬ 
quired by the body, 114-116, 

237- 238; and its function in 
health, 121-128; artificially- 
softened, 235-236; as a medi¬ 
cine, 124-126; best beverage, 
234; chemical composition of, 
111—112; chief properties of, 
112, 113; distilled, 118, 234; 
effect of heat on, 114; hard, 
235; in the human body, 114; 
mineral, 126; necessary to 
life, 126-127; pure drinking, 
118-119, 234; purifying, 120- 
121; result of drinking an 
excess of, 124; should be 
tested, 227; soft, 235; spring, 
118; 119, 234-235; tempera¬ 
ture of drinking, 117; the 
“universal solvent,” 113, 127; 
well, 118, 119; when taken, 

238- 239; with meals, 121-123. 

Weight, of grown persons, 300. 

Well, diagram of a, 118. 

Well water, see Water, well. 

Wheat, 145, 158; as affected by 
milling, 162-164; as food, 161; 
composition of, 158-159; dif¬ 
ference between barley and, 
172-173; difference between 
corn and, 166-168; difference 
between rye and, 171; form 
best for food, 161. 

Whiskey, 259. 

Wide ratio, 306. 

Will, 387. 

Wind, 2-3. 

Windpipe, 21, 30, 40; and 
swallowing, 330. 

Xenon, 13. 

Yellow fever, 59. 

Zein, 167, 364. 



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